Pathway to Japanese Literature

The D-Slope Murder Case

Part One: Facts

It was a muggy evening in early September.

I was sipping iced coffee at Shirabai-ken, a café I frequented located midway along D Slope’s main street.
At the time, I had just graduated from school and had no proper occupation to speak of; my daily routine consisted of lazing around my boarding house reading books or, when that grew dull, wandering out for aimless walks and visiting inexpensive cafés.
This Shirabai-ken was not only close to my boarding house but also situated such that I inevitably passed by its front no matter where I wandered on my walks, which was why I frequented it most often; but I, being a man with a bad habit, tended to linger whenever I entered a café.
This was partly due to my naturally small appetite and partly because my purse was light; rather than ordering a full Western meal, I would ask for refills of cheap coffee two or three times and sit still for an hour or two.
That being said, it wasn’t as though I had any particular fancy for the waitresses or was teasing them.
Well, I suppose it was somewhat more lively than my boarding house and simply felt comfortable.
That evening as well, per my usual routine, I was taking a full ten minutes to drink a glass of iced coffee while settled at my regular table facing the street, absentmindedly gazing out the window.

Now, this D Slope where Shirabai-ken stood was once famous for its chrysanthemum doll displays. The narrow street had been widened through urban reforms to become a major thoroughfare designated as a road of several ken—though this transformation was still recent enough that vacant lots lingered here and there along both sides of the avenue, and the story takes place during a time when it was far lonelier than now. Across the main street, directly opposite Shirabai-ken, there was a used bookstore. The truth was, I had been watching its storefront for some time now. It was a shabby used bookstore in a rundown part of town, hardly a view worth gazing at, but I felt a peculiar interest in it. The reason was this: I had recently become acquainted with a peculiar man at this Shirabai-ken named Akechi Kogorō, who struck me as quite eccentric yet undeniably intelligent; what had particularly endeared him to me was his fondness for detective novels. I had heard from him recently that a woman he had known since childhood was now the wife of this used bookstore’s owner. From what I remembered after buying books there two or three times, the wife of this used bookstore’s owner was quite a beauty; though there was nothing specific you could point to, she had some indescribable sensual quality that drew men in. Since she always kept shop at night, I thought she must certainly be there tonight too, and searched throughout the store—though it was cramped with only a two-and-a-half ken frontage—but found no one. Assuming she would come out sooner or later, I kept my eyes fixed there, waiting.

But the wife still did not come out.
At that moment, as I grew thoroughly fed up and was about to shift my gaze to the neighboring clock shop—
I suddenly noticed the latticed shoji door at the boundary between the shop and back room snap shut.—That shoji was what experts call a *munmado* (no-window), where the central area typically covered with paper instead features intricate vertical double latticework that can be opened or closed— How peculiar!
Used bookstores are businesses prone to shoplifting, so even when unmanned, someone usually keeps watch through gaps in the shoji screen—yet they had closed off those very peepholes. Cold weather might excuse it, but on such a sweltering September evening? Above all, that tightly shut shoji was downright strange.
When I considered all this, it seemed something must be happening in the back room of the used bookstore, and I found myself unable to look away.

Speaking of the used bookstore owner’s wife, I once overheard the waitresses at this café spreading a strange rumor about her. Apparently, it was a continuation of their gossip about women and girls they encountered at the public bathhouse: “The used bookstore’s Ms. Kami may be such a beauty,” one said, “but when she’s naked, her whole body’s covered in wounds—marks from being beaten and pinched, no doubt.” “They don’t seem to have a bad marriage though—how odd,” another chimed in. Then a different woman picked up the thread: “Even Asahi-ya’s Ms. Kami from that row of soba shops often has injuries.” “Those must be from beatings too…” Now, I didn’t dwell deeply on what these rumors meant, simply assuming the husbands were being cruel—but dear readers, that proved far from true. Though trivial at first glance, this matter later revealed its crucial significance to the entire story.

Be that as it may, I had been staring at the same spot for about thirty minutes.
Was it what they call a premonition? Somehow, with the sense that something might happen if I looked away, I found myself unable to turn my eyes elsewhere.
At that moment, Akechi Kogorō—whose name had just come up earlier—passed by outside the window, wearing his usual coarse striped yukata and walking with an oddly exaggerated shoulder-swinging gait.
When he noticed me, he nodded and came inside, ordered an iced coffee, turned toward the window like me, and sat down next to me.
And when he noticed that I was staring at one spot, he followed my gaze and likewise looked toward the used bookstore across the street.
Moreover, strangely enough, he too began to stare intently in that direction with evident interest, without averting his eyes even slightly.

We gazed at the same spot as if by prior agreement while exchanging various idle remarks.
What topics we discussed between us at that time—I have now even forgotten—and since they bear little relevance to this story, I shall omit them, though it is certain they concerned crime and detectives.
When I tentatively brought up an example and considered it,

“Is a crime that absolutely cannot be discovered an impossibility?”
“I think there’s considerable potential for such,” he replied.
“Take Jun'ichirō Tanizaki’s *Tōjō*, for instance.”
“Crimes of that nature are scarcely ever uncovered.”
“Though in that novel,” Akechi added, “it’s presented as being solved by a detective—that being a product of the author’s remarkable imagination.”

“No, I don’t think so.”
“Putting practical matters aside, theoretically speaking, there’s no such thing as a crime a detective cannot solve.”
“It’s just that the current police force doesn’t have any great detectives like the one in *Tōjō*,” I said.

Our conversation went something like this.
But at a certain moment, the two of us fell silent as if by prior agreement.
While we had been talking without looking away, an intriguing incident had occurred at the used bookstore across the street.

“You seem to have noticed as well.”

When I whispered this, he responded immediately.

“It must be a book thief.”
“Something feels off.”
“I’ve been watching since I came in here.”
“This makes four people now.”

“It hasn’t even been thirty minutes since you arrived—four people in half an hour seems strange.”
“I’d been watching that spot since before you came.”
“About an hour ago—you know that shoji screen?”
“I saw its latticework close shut, and kept watch ever since.”

“Couldn’t someone from the household have gone out?”

“But that shoji screen never opened even once.”
“If they left through the back entrance… It’s certainly strange no one’s been present for thirty minutes.”
“How about it?”
“Shall we go investigate?”

“Agreed.”
“Even if nothing’s amiss inside, something may have occurred outside.”

While thinking how interesting it would be if this turned out to be a criminal case, I left the café.
Akechi must have been thinking the same thing.
He too was considerably excited.

The used bookstore was of a common type: the entire shop had an earthen-floored area with floor-to-ceiling bookshelves attached to the front and both sides, their lower sections serving as platforms for displaying books. In the center of the earthen-floored area stood a rectangular platform, like an island, also used for arranging and stacking books. The right side of the front bookshelf had a gap of about three feet, forming a passage to the back room where the aforementioned single shoji screen stood. Typically, either the owner or his wife would be perched on the half-tatami mat of tatami flooring in front of this shoji screen, keeping watch.

Akechi and I went as far as the tatami-floored area and called out loudly, but there was no response. Sure enough, there seemed to be no one there. When I slightly opened the shoji screen and peered into the back room, the interior lay pitch dark with the light off, though a human-like figure appeared collapsed in the corner. Suspicious, I called out again, but received no answer.

“Never mind. Let’s go up and take a look.”

At that, we clomped our way into the back room. Akechi twisted the electric light switch. The instant illumination made us both gasp—there in the corner of the brightened room lay a woman’s corpse.

“This must be his wife,” I finally said. “Doesn’t it look like her neck was strangled?”

Akechi had moved closer and was examining the corpse. "There's no hope of resuscitation. I need to notify the police quickly. I'll go to the public telephone. You keep watch here. It would be better not to inform the neighbors yet. We mustn't let the clues be destroyed."

He left these commanding words and dashed off to the public telephone about half a block away.

Though I'd always been quite adept at discussing crimes and detectives in theory, this was my first time actually confronting one. There was nothing I could do. I could do nothing but stare intently at the state of the room.

The room was a six-tatami single chamber. At the rear, the right section was separated by a narrow veranda, leading to a roughly two-tsubo garden and toilet; beyond the garden stood a wooden plank fence.
—It being summer and having been left open, the view was completely unobstructed.— The left half-room had sliding doors; beyond them lay a wooden area of about two tatami mats, adjoining a narrow sink space by the back entrance, where a waist-high shoji screen remained closed.
On the right side, four sliding doors were closed, and inside appeared to be a staircase leading to the second floor and a storage area.
It was the utterly commonplace layout of a cheap tenement house.

The corpse lay near the left wall, its head facing toward the shop area. I tried to avoid disturbing the scene as it had been at the time of the crime—partly because I felt uneasy—and kept myself from approaching the corpse. However, it was a small room, and even if I tried not to look, my eyes would naturally drift in that direction. The woman was wearing a coarse medium-patterned bathrobe and lay almost on her back. However, the robe had been hiked up to above the knees, exposing the thighs, yet there was no sign of resistance. The area around the neck was not clearly visible, but there appeared to be purple strangulation marks.

The main thoroughfare out front saw an unceasing flow of people and vehicles.
People were talking loudly, dragging their weather clogs with a clatter, or drunkenly belting out popular songs—an utterly peaceful scene.
And behind a single shoji screen, a woman lay brutally murdered.
What irony.
I became strangely sentimental and stood there in a daze.

“They should be here soon.”

Akechi returned, out of breath.

“Oh. I see.”

I somehow found even speaking to be a burden.

For a long time, the two of them exchanged glances without saying a word.

Before long, a uniformed police officer arrived together with a man in a suit. The uniformed one—as I later learned—was the judicial officer from K Police Station, while the other man’s appearance and belongings identified him as a police physician from the same station. We gave the judicial officer a general account of events from the beginning. Then I added:

“When Akechi-kun entered the café, I happened to check the clock—it was just past eight-thirty—so I believe the shoji lattice must have been closed around eight o’clock. At that time, there was definitely a light on inside. Therefore, we can confirm someone alive was in this room until at least eight o’clock.”

While the judicial officer listened to our statements and took notes in his notebook, the police physician had completed a preliminary examination of the corpse. He waited for our words to trail off and spoke.

“It’s strangulation.”
“Done by hand.”
“Look here.”
“This purple discoloration shows finger marks.”
“The bleeding here comes from nail impacts.”
“Given the thumb mark on the neck’s right side, it was done with the right hand.”
“Correct.”
“Death likely occurred less than an hour ago.”
“Though naturally, resuscitation is impossible now.”

“They pressed down from above?”
The judicial officer mused aloud.
“Yet there’s no sign she resisted… They must have acted with sudden force.”
“Brutal strength.”

Then he turned to us and asked what had become of the master of the house. But of course there was no way we could have known. Thereupon Akechi took the initiative and went to fetch the owner of the neighboring clock shop.

The exchange between the Judicial Officer and the clock shop owner was generally as follows.

“Where has the master of the house gone, hmm?”

“The master of this house goes out every night to set up his used book stall, so he never returns before around twelve o’clock.”
“...he never returns before around twelve o’clock, sir.”

“Where do you set up the night stall?”

“He often goes to Ueno’s Hirokoji Avenue, I believe.”
“As for where he went tonight, I’m afraid I cannot say for certain.”
“Sir.”

“About an hour ago, didn’t you hear some sort of noise?”

“When you say ‘noise’…”

“Isn’t it obvious? The scream when this woman was being killed, the sound of a struggle…”

“I did not hear any particular noise of that sort, but…”

In the midst of this commotion, neighbors who had heard the news gathered, and with curious passersby stopping to gawk, the front of the used bookstore became packed with a crowd.
Among them was the other neighbor—the mistress of the tabi shop next door—who had come to assist the clock shop owner.
And she also stated that she had heard no noises whatsoever.
In the meantime, it appeared that the neighbors, after conferring, had dispatched a messenger to the owner of the used bookstore.

Just then, the sound of an automobile stopping out front could be heard, and several people came clattering in.
They were a party consisting of court personnel who had rushed over upon an urgent notice from the police, Chief of the K Police Station who happened to arrive at the same time by coincidence, and Detective Kobayashi—then rumored to be a famous detective.—Of course, this was something I learned later, for I had a friend who was a judicial reporter and was quite close with Detective Kobayashi in charge of this case, so I was able to hear various details from him afterward.—The first-arriving judicial officer explained the situation thus far before these people.
We too had to repeat our previous statements.

“Let’s close the front door.”

Suddenly, a man who looked like a low-ranking company employee—wearing a black alpaca coat and white trousers—shouted loudly and briskly began shutting the door. This was Detective Kobayashi. Having thus driven away the gawkers, he then set about his detective work. His methods were thoroughly brazen, and he seemed to pay no heed whatsoever to the Prosecutor or Chief. He operated alone from start to finish. The others seemed like mere spectators who had come solely to observe his agile movements. He first examined the corpse. He was particularly thorough in examining the area around the neck,

“There’s nothing distinctive about these finger marks.”
“In other words, there are no clues aside from the fact that an ordinary person pressed down with their right hand.”

He said, looking toward the Prosecutor.
Next, he proposed stripping the corpse naked for examination.
Thereupon, like in a parliamentary secret meeting, we bystanders had to be driven out to the front room of the shop.
Therefore, we could not clearly know what discoveries were made during that time, but it is safe to assume that they must have taken note of the numerous fresh wounds on the corpse’s body.
That was the thing the café waitress had been gossiping about.

Before long, this closed-door meeting disbanded, but we refrained from entering the back room and instead peered into it from the tatami-matted boundary between the front and rear spaces of the shop. Fortunately, being the incident's discoverers and because they later needed Akechi's fingerprints, we managed to remain until the end without being expelled—or more accurately, we were effectively detained. However, since Detective Kobayashi's activities spanned both indoor and outdoor areas rather than being confined to the back room alone, we who stayed fixed in one place could hardly have grasped his investigative movements. Yet through fortunate circumstance, with the Prosecutor having stationed himself almost motionless in the back room throughout, each time the detective came and went we could hear every report of findings without omission. Based on these reports, the Prosecutor had his clerk transcribe materials for the official record.

First, a search was conducted of the back room where the corpse had been found, but there appeared to be no left-behind articles, footprints, or anything else that caught the detective's eye.
Except for one thing.

"There are fingerprints on the light switch."
The detective—who was sprinkling white powder on the black ebonite switch—said.
"Considering the circumstances before and after, there's no doubt the culprit turned off the light.
But which of you turned this on?"

“It was me,” Akechi answered.

“I see.”
“Please allow me to take your fingerprints later.”
“Let’s be careful not to touch this light and take it away as it is.”

Then, the detective went upstairs and did not come down for some time, but upon coming down, he immediately declared he would examine the alley and left.
Had about ten minutes passed? Before long, he returned with a man in tow, still holding the lit flashlight in one hand.
He was a dirty man around forty years old, dressed in a soiled crepe shirt and khaki-colored trousers.

“The footprints are completely useless,” the detective reported. “The area around this back entrance—perhaps because it gets little sunlight—is terribly muddy, with countless geta tracks scattered everywhere. It’s utterly impossible to make sense of them. Now, regarding this man here—” Detective Kobayashi pointed at the man he had just brought in “—he is an ice cream vendor who had his stall at the corner where this back alley exits. If the culprit fled through the back entrance, the alley being a dead end, they would have inevitably been spotted by this man. Now, you—answer my questions once again.”

At that point, the ice cream vendor and the detective began their exchange of questions and answers.

“Was there anyone who entered or exited this alley around eight o’clock tonight?”

“There hasn’t been a single person—not even a stray cat has passed through since sunset.”
The ice cream vendor answered with practiced efficiency.

“I’ve been permitted to run my stall here for years now, but even the residents of this tenement hardly ever come through there at night. What with that unstable footing and how pitch-dark it gets.”

“None of your customers went into the alley?”

“There were none of those either.”
“All my customers ate their ice cream right before my eyes and went straight back where they came from.”
“That’s absolutely certain.”

Now, if we were to trust this ice cream vendor's testimony, then even if the culprit had fled through this house's back entrance, he would not have exited via the alley—the sole passageway from that back entrance.
That being said, he did not exit through the front either—a certainty since we were watching from Hakubaiken.
So what on earth did he do?
According to Detective Kobayashi's theory, this must be either that the culprit was hiding in one of the tenement houses lining both sides of the alley or that he was among the tenants themselves.
Admittedly, there was a potential escape route via the roof from the second floor; however, according to their examination of the second floor, the front windows had fixed lattices showing no signs of being tampered with, and even the rear windows—given this heat—were left wide open in every house, with some people even cooling themselves on laundry-drying balconies, making escape from there seem rather difficult.
So that was his conclusion.

Thereupon, a brief discussion regarding investigative strategy was held among the officials, ultimately resulting in a decision to divide tasks and conduct a house-to-house search of the neighborhood.
That said, with only eleven tenement houses lining both sides of the alley combined, this posed no great difficulty.
Simultaneously, the house interior was searched again with exhaustive thoroughness—from beneath the floorboards up to the attic.
Yet these efforts not only proved fruitless but appeared to render matters even more perplexing.
The reason was this: it emerged that the confectionery shop owner two doors down from the used bookstore had been on his rooftop drying platform playing the shakuhachi from dusk until mere moments earlier—and he had been positioned such that he could not possibly have failed to notice anything occurring at the second-floor window of the bookstore throughout that entire time.

Dear readers, the case had grown quite intriguing.
Where did the culprit enter and escape from? Not through the back entrance, not through the second-floor window—and of course not through the front.
Had he never existed from the start, or had he vanished like smoke?
But the mystery did not end there.
Detective Kobayashi brought two students before the Prosecutor—students who had made a truly peculiar statement.
They were pupils from an industrial school renting rooms in the tenement on the back side; neither seemed prone to wild fabrications, yet their testimony only deepened the enigma.

In response to the Prosecutor’s questions, they answered roughly as follows.

“I was standing in front of this used bookstore around eight o’clock exactly, looking through a magazine on the stand there.”
“Then there was some noise from the back, so when I suddenly looked up at this shoji screen—though the screen itself was closed—the lattice portion was open, and through that gap I saw a man standing there.”
“But since I looked up just as he closed that lattice at almost the same moment, I couldn’t see any details properly. Still, I’m certain it was a man from how his sash was tied.”

“And aside from it being a man—did you notice anything else? His build perhaps? Or the pattern of his clothes?”

“Since what I saw was from the waist down, I couldn’t really tell his build, but his clothes were black.”
“It might have had thin stripes or a splashed pattern, though.”
“In my eyes, it appeared to be solid black.”

“I was also looking at books with my friend,” said the other student, “and in the same way, I noticed a noise and saw the lattice close. But that man was definitely wearing white clothes. A pure white garment without any stripes or patterns.”

“Isn’t this odd? Then one of you must be mistaken.”

“There is absolutely no mistake.”

“I’m not lying either.”

What did these two students’ peculiar statements signify? Astute readers have likely noticed something by now.
In fact, I noticed that as well.
However, the court and police officials did not seem to dwell too deeply on this point.

Before long, the used bookstore owner—the husband of the deceased—returned upon hearing the news.
He was a delicate, young man who did not look like a used bookstore owner, but upon seeing his wife’s corpse, he appeared to be of a timid disposition; though he made no sound, tears streamed down his face.

Detective Kobayashi waited for him to calm down before beginning his questioning.
The Prosecutor also interjected.
But what disappointed them was that the owner had no inkling of who the culprit might be.
He said, “Of all people, she wasn’t one to invite others’ resentment,” and wept.
Moreover, through his own inquiries, it had been confirmed this was no burglar’s work.
There were investigations into the owner’s history, his wife’s background, and other matters, but since nothing particularly suspicious emerged and they bore little relevance to the story’s thread, I shall omit them.
Finally came the detective’s questions about the numerous fresh wounds on the deceased’s body.
The owner had hesitated greatly but finally admitted he himself had inflicted them.
Yet when pressed repeatedly about the reason, he gave no clear answer.
However, since it was established he’d been manning his night stall all evening, even if those were abuse marks, there could be no grounds to suspect him of murder.
Perhaps the detective thought likewise, for he did not delve deeper.

And so, that night’s interrogation was temporarily concluded.
We were made to write down our addresses and names, Akechi had his fingerprints taken, and by the time we set out for home, it was already past one o’clock.

If there were no oversights in the police’s search and the witnesses did not lie, then this was truly a perplexing case.
Moreover, as we later learned, all subsequent interrogations conducted by Detective Kobayashi from the following day onward proved utterly fruitless, and the case remained exactly as it had been on the night of its occurrence—not progressing an inch.
All the witnesses were people worthy of trust.
The residents of the eleven tenement houses also had no grounds for suspicion.
The victim’s hometown was also investigated, but this too yielded nothing unusual.
At the very least, Detective Kobayashi—he, as I mentioned before, was a man rumored to be a great detective—had no choice but to conclude that this case was utterly inexplicable, given the extent of his exhaustive search.
I later heard that, to their dismay, nothing but Akechi’s fingerprints could be found on the light switch—the sole piece of evidence Detective Kobayashi had pleaded to take back.
Perhaps because Akechi had been flustered during that moment, numerous fingerprints had been left there, but every single one was his own.
The detective concluded that Akechi’s fingerprints had likely erased the culprit’s.

“Dear readers, as you read this story, wouldn’t you be reminded of Poe’s *The Murders in the Rue Morgue* or Doyle’s *The Adventure of the Speckled Band*?”
In other words, wouldn’t you imagine that the culprit in this murder case isn’t a human but something like an orangutan or an Indian venomous snake?
I had actually thought of that as well.
However, I couldn’t imagine such creatures existing around Tokyo’s D Slope; moreover, there were witnesses who claimed to have seen a man through the shoji screen’s gaps.
Not only would apes or monkeys have left footprints, but they would also have been noticed by someone.
And the finger marks on the deceased’s neck were indeed those of a human.
Even if a snake had coiled around her, such marks wouldn’t remain.

Be that as it may, Akechi Kogorō and I, while heading home that night, were extremely excited and talked about all sorts of things. To give an example, well, things like this.

“You know about that Parisian Rose Delacourt case that served as material for Poe’s *The Murders in the Rue Morgue* and Leroux’s *The Yellow Room*, don’t you? That mysterious murder case from over a hundred years ago that remains unsolved even today. I remembered that, you know. Tonight’s case also resembles that one in having no trace of the culprit’s departure, don’t you think?” said Akechi.

“That’s true.”
“It’s truly mysterious.”
“People often say serious crimes like those in foreign detective novels don’t occur in Japanese buildings, but I certainly don’t think that’s the case.”
“After all, we have actual cases like this one.”
“I somehow feel like I want to try investigating this case myself, though I don’t know whether I can do it or not.”

And so, we bid farewell at a certain side street.
At that moment, I remember seeing Akechi’s retreating figure—turning the corner of the side street, walking briskly with his signature shoulder-swaying gait—his boldly striped yukata rendering him starkly visible against the darkness.

(Continued) Deduction

Now then, about ten days after the murder incident, I visited Akechi Kogorō’s lodgings.
What had Akechi Kogorō and I done, thought, and concluded regarding this case during those ten days?
Readers will be able to sufficiently infer those matters through the conversation exchanged between him and me on this day.

Up until then, I had only ever run into Akechi at cafés, and this was my first time visiting his lodgings, but since I had already heard where he lived, it wasn’t difficult to find.
I stood in front of a seemingly appropriate tobacco shop and asked the woman whether Akechi was there.

“Yes, he’s here.”
“Please wait a moment—I’ll call him right away.”

She said this, went to the staircase entrance visible from the shopfront, and called out loudly to Akechi.
He was renting a room on the second floor of this house.
Then,

“Oh.”

With this strange reply, Akechi came creaking down the stairs. When he noticed me, he made a surprised face and said, “Ah, do come up.”
I followed him up to the second floor.
But the moment I carelessly stepped into his room, I was utterly dumbfounded.
The state of the room was far too abnormal.
I hadn’t been unaware that Akechi was eccentric, but this was beyond eccentricity.

It was nothing but—the four-and-a-half tatami mat room was buried in books. Only a small portion of the tatami was visible at the center; the rest were mountains of books. Along all four walls and sliding doors, these embankments of books filled nearly the entire lower half of the room, narrowing toward the top until they pressed close to the ceiling from every direction. There were no other furnishings or items. It was to such an extent that one couldn’t help but wonder how he managed to sleep in this room. First of all, there was no place for both host and guest to sit, and if one were to carelessly move even slightly, they might immediately be crushed by a collapse of the book embankment.

“It’s rather cramped here, I’m afraid—and there are no zabuton cushions either. My apologies, but would you mind sitting on some of the softer-looking books?”

I pushed my way into the mountain of books and finally found a place to sit, but so overwhelmed was I that for a while, I blankly looked around the area.

I must here provide a brief explanation regarding the character of Akechi Kogorō, master of such an eccentric room. However, as my association with him was of recent origin, I knew nothing about what manner of background he possessed, how he clothed and fed himself, or what purpose guided him through life—but it was certain he was a sort of drifter without any particular occupation. If pressed to categorize him, one might call him a student—though a student of exceedingly unconventional sort. There had been an occasion when he declared, “I study humans,” but at that time I had not fully grasped what this meant. What *was* understood was that he maintained an extraordinary interest in crime and detection, coupled with alarmingly extensive knowledge of these subjects.

He was about the same age as me, likely not yet past twenty-five.
He was rather on the slim side and, as I mentioned earlier, had a peculiar habit of swinging his shoulders when he walked—though it was by no means the swagger of a brawny hero. To draw an odd comparison, his gait reminded one of that rakugo storyteller Kanda Hakuryū—the one-armed performer.
Speaking of Hakuryū, Akechi resembled him in everything from facial features to voice—readers who have never seen Hakuryū should imagine, among those you know, a face that couldn’t be called handsome yet held an inexplicable charm and genius-like quality—though Akechi’s hair hung longer and tangled wildly.
And it was his habit to frequently run his fingers through that disheveled mop during conversations, as if deliberately worsening its tangled state.
He seemed utterly indifferent to his attire, always clad in a cotton kimono secured with a carelessly wrinkled casual sash.

“It’s good of you to come.”
“We haven’t met since then—what of that D-Slope case?”
“The police still haven’t caught any scent of the culprit, have they?”

Akechi said this while—in his characteristic manner—running fingers through his disheveled hair and scrutinizing my face.

“Truthfully, I came today to speak with you about that very matter.”
Thus I began, faltering over how to broach the subject.

“Since then, I’ve considered various angles. Not just considered—I even conducted field investigations like a detective,” I began hesitantly. “And in truth, I’ve reached a conclusion. I came to share it with you…”

“Oh?” Akechi replied, tousling his hair as he stared intently. “How splendid. I’d very much like to hear the details indeed.”

I didn’t miss the flicker of contempt—and relief—in his gaze that seemed to ask, “What could you possibly grasp?” Yet paradoxically, that look bolstered my wavering resolve. Leaning forward, I launched into my explanation with renewed fervor.

“I have a friend who’s a newspaper reporter, you see—he’s on good terms with Detective Kobayashi, the one handling that case.”
“Through him, I managed to get detailed information about the police’s situation, but it seems they still can’t establish a proper investigative policy.”
“Of course they’re conducting various activities, but they haven’t been able to grasp any solid prospects.”
“That light switch we mentioned earlier, you know.”
“That didn’t yield results either.”
“They discovered that only your fingerprints were there.”
“The police’s theory is that your fingerprints probably ended up obscuring the criminal’s.”
Having learned how troubled the police were, I grew even more motivated to investigate.
“So what do you think this conclusion I reached might be? And why do you suppose I came to tell you before going to the police?”

“Be that as it may, I had noticed something from the very day of that incident. You remember, don’t you? The two students made entirely different statements about the color of the man suspected to be the culprit’s kimono. One said it was black; the other claimed it was white. However unreliable human eyes may be, isn’t it strange to mistake completely opposite colors like black and white? I don’t know how the police interpreted it, but I believe both statements aren’t incorrect. Do you understand? You see, the culprit wore a kimono with alternating black and white stripes—thick vertical black stripes on a yukata, like those rented at inns. Now, why would one witness see pure white and the other pure black? Since they viewed it through gaps in the shoji screen’s lattice, precisely at that moment, one witness’s line of sight aligned with a gap and the white base of the garment, while the other’s aligned with a gap and the black base. This may be an unusual coincidence, but it’s by no means impossible. And in this case, there’s no other way to think.”

“Now, I’ve determined the striped pattern of the culprit’s kimono, but this merely narrows the scope of the investigation and doesn’t yet provide a definitive conclusion.”
“The second piece of evidence lies in those fingerprints on the light switch.”
“Through my journalist friend’s connections—the one I mentioned earlier—I had Detective Kobayashi thoroughly examine those fingerprints—your fingerprints, you know.”
“As a result, I confirmed that what I’d been thinking was indeed correct.”
“By the way, if you have an inkstone, could you lend it to me for a moment?”

At that point, I conducted an experiment to demonstrate.
First, I borrowed an inkstone, lightly coated my right thumb with ink, and pressed a single fingerprint onto a sheet of washi paper from my pocket.
Then, after waiting for the fingerprint to dry, I once again applied ink to the same finger and, changing the finger's orientation this time, pressed it carefully over the previous fingerprint.
Then, two overlapping fingerprints clearly appeared there, intricately intertwined.

“The police interpret that your fingerprints overlapped the criminal’s and erased them, but as this experiment shows, that’s impossible. No matter how hard you press, since fingerprints consist of lines, traces of the previous fingerprints should remain between them. If the earlier and later fingerprints were completely identical and pressed in exactly the same manner—since each line would align—the later ones might conceal the earlier ones. But such a scenario is practically impossible, and even if it were possible, in this case the conclusion remains unchanged.”

“However, if the culprit was the one who turned off that light, their fingerprints must remain on the switch. I thought perhaps the police had overlooked earlier fingerprints between the lines of yours, so I examined it myself—but there wasn’t a single trace of such a thing. In other words, on that switch—both before and after—only your fingerprints have been left. As for why the bookstore people’s fingerprints weren’t there… I’m not entirely sure about that—but it’s likely that light in that room was left on and had never been turned off.”

“You—what do you think all these things are telling us?”
“This is how I see it.”
“A man wearing a kimono with coarse vertical stripes—perhaps he was the dead woman’s childhood friend, and something like unrequited love could be considered as a motive—knew that the bookstore owner would be away running his night stall and attacked the woman during his absence.”
“Since there are no signs of her having made a sound or resisted, she must have been well acquainted with the man.”
“And so, the man, having successfully achieved his objective, turned off the light and left to delay the discovery of the corpse.”
However, this man’s fatal oversight was his ignorance of the open lattice in the shoji screen and the fact that, upon closing it in surprise, he was inadvertently seen by two students who happened to be in front of the store.
Then, the man stepped outside, but he suddenly realized that when he had turned off the light, his fingerprints must have remained on the switch.
He absolutely had to erase this.
However, it would be dangerous for him to sneak back into the room using the same method.
At that point, the man came up with a brilliant idea.
It was to make himself the discoverer of the murder case.
“By doing so, not only could he naturally turn on the light himself and eliminate any suspicion regarding the previous fingerprints, but since no one would ever suspect that the discoverer was the culprit, it offered a twofold advantage.”
In this way, he was nonchalantly observing the police’s methods.
He even boldly gave testimony.
Moreover, the result fell right into his hands, you know.
“Even after five days, even after ten days, no one came to arrest him, you know.”

With what expression had Akechi Kogorō been listening to my account?
I had expected him to either show some reaction or interject midway through my explanation.
Yet to my astonishment, not a single expression surfaced on his face.
While he had always been someone who kept his emotions hidden, this composure felt excessive.
He sat silently throughout, repeatedly tousling his perpetually disheveled hair.
I pressed on to my final point, wondering just how brazen a man I must be.

“You’ll surely retort then, ‘So where did the culprit enter from and where did he escape?’”
“Indeed, unless that point is clarified, understanding all other matters would be utterly meaningless.”
“But regrettably, I was the one who uncovered that as well.”
“According to that night’s investigation results, there appeared to be no traces whatsoever of the culprit having left.”
“However, since a murder had occurred, the culprit must have come and gone—so we can only conclude there was some oversight in the detectives’ search.”
“The police too seemed to have put considerable effort into that, but unfortunately, they could not measure up to a mere student like me.”

“Well, it’s actually a rather trivial matter, but this is what I thought.”
“Given how thoroughly the police have been investigating, there should be nothing suspicious about the people in the neighborhood.”
“If that were the case, then perhaps the culprit passed through using some method where even if someone saw them, they wouldn’t realize it was the culprit—and even if there were people who witnessed it, they probably didn’t consider it an issue at all, I thought.”
“In other words, by exploiting a blind spot in human attention—just as our eyes have blind spots, so too does our attention—he may have hidden himself, much like a magician effortlessly conceals a large object right before the audience’s eyes.”
“So, what I focused on was Asahiya, the soba shop one store over next to that used bookstore.”

To the right of the used bookstore were a watch shop and a confectionery, and to the left were a tabi shop and a soba shop.

“I went there and asked if there had been a man who borrowed the restroom around eight o’clock on the night of the incident.”
“You’re familiar with Asahiya, I assume—the shop connects via an earthen floor all the way to the back gate, and since the restroom is right next to that back gate, someone could easily pretend to borrow the restroom, exit through the back entrance, and then come back in without any trouble.”
“The ice cream vendor in question had set up shop at the corner just beyond the alley—there was no way he could have been found—and since the person in question was a soba shop owner, borrowing the restroom would have been extremely natural.”
“When I asked, it turned out that the wife was absent that night, and only the master was present in the shop, making it all too convenient.”
“You—what a splendid idea this is—don’t you think?”

“And sure enough, there had been a customer who used the restroom right around that time.
“However, unfortunately, the owner of Asahiya hadn’t remembered the man’s facial features or the stripes on his kimono at all—I’d promptly reported this matter to Detective Kobayashi through that friend of mine.”
“Detective Kobayashi had investigated the soba shop himself, but he couldn’t uncover anything beyond that—””

I paused my words slightly and gave Akechi an opportunity to speak.
Given his position, he should have been unable to remain silent without uttering a single word at this point.
Yet he remained composed, still scratching his head.
I, who had until now employed indirect phrasing out of respect, found myself compelled to shift to directness.

“You, Akechi-kun, must understand what I’m saying. Irrefutable evidence points directly at you. To confess honestly—though I still cannot truly bring myself to suspect you in my heart—with all this evidence arrayed before us, there’s simply no alternative. I… investigated thoroughly whether anyone in that tenement possessed a yukata with bold vertical stripes, yet found not a single soul. And that stands to reason. Even among those wearing striped yukatas, people who would don such garish patterns matching that latticework are exceedingly rare. Moreover, both the fingerprint trick and the restroom pretext demonstrate true ingenuity—feats no one but a criminologist of your caliber could execute. Most damningly—though you claimed childhood ties with the victim’s wife—when they conducted her background check that night, you listened nearby yet never once disclosed this connection, did you?”

“Now, in that case, the sole remaining reliance is the presence or absence of an alibi.”
“However, even that is no good.”
“Do you remember that night on your way back—where you were before coming to Hakubaiken—I asked you about that?”
“You answered that you had been walking around that area for about an hour.”
“Even if someone had seen you taking a stroll, it would be quite common for you to borrow the soba shop’s restroom midway through your walk.”
“Akechi-kun, is what I’m saying wrong?”
“Well?”
“If you can, let’s hear your defense, shall we?”

Dear readers, what do you suppose the eccentric Akechi Kogorō did when I pressed him like this?
Do you imagine he prostrated himself in shame?
Far from it—he rattled my composure in a wholly unexpected manner.
That is to say, he suddenly burst into uproarious laughter.

“My apologies—I never meant to laugh, but you were being excessively earnest,” Akechi said by way of explanation. “Your theory proves rather intriguing. I find myself gratified to have discovered a companion of your caliber. Yet regrettably, your deductions remain excessively superficial and materialistic. Consider this: Regarding my connection with that woman—did you investigate what manner of childhood bond we shared? Whether romantic entanglements ever existed between us? Whether present resentments linger? Could you not infer even such fundamentals? My silence that night stemmed from simple ignorance. I possessed no pertinent knowledge whatsoever—we’d parted before my elementary schooling began. Though I must note—through recent chance discoveries, we’d conversed on two or three occasions.”

“Then, how should we consider the matter of the fingerprints?”

“Do you think I’ve been doing nothing since then? I’ve been quite busy with this myself, you know. I wandered around D Slope nearly every day. I made particular visits to the used bookstore. There I cornered the master and questioned him thoroughly—having disclosed that I knew his wife at that point, which actually worked to my advantage—just as you learned about police movements through a reporter, I’d extracted information from that bookseller.”
“As for those fingerprints—since they became clear so quickly—I found it suspicious too and checked, but… haha… It’s absurdly simple. The filament had broken. No one turned it off at all.”
“The light didn’t come on because I flipped the switch—when I jostled the lamp in my haste, the severed tungsten filament momentarily reconnected.”
“Of course only my fingerprints were on the switch.”
“That night, you claimed you saw light through the shoji screen’s gaps? Then the bulb must have burned out afterward.”
“Old bulbs often fail spontaneously like that.”
“As for the culprit’s clothing color—this would be better explained by…”

He said this and began excavating through the mountain of books around him here and there, but before long, he dug out a single worn-out Western book.

“You—have you read this? Münsterberg’s *Psychology and Crime*. Read just the first ten lines or so of this ‘Illusions’ chapter, if you would.”

As I listened to his confident arguments, I gradually began recognizing my own failures.
Following his instruction, I took the book and read.
What lay there was roughly as follows.

There was once an automobile crime incident.
In court, one of the witnesses, who had sworn to tell the truth, claimed that the road in question was completely dry and dusty, while another witness swore that after rainfall, the road was muddy.
One claimed that the automobile in question had been moving slowly, while the other stated that he had never seen an automobile traveling as fast as that one.
Furthermore, the former claimed there had been only two or three people on that village road, while the latter stated there had been many passersby—men, women, and children.
These two witnesses were both respectable gentlemen—people who had no reason to distort the facts for any gain.

After waiting for me to finish reading that, Akechi turned the pages of the book further and said.

“This actually happened. Now, there’s a chapter here titled ‘The Memory of Witnesses.’ In its middle section, there’s an account of a deliberately planned experiment. Since it happens to discuss clothing colors—though it may be tedious—just read this part briefly.”

It was an article as follows.

(Omitted) To give one example: the year before last (this book was published in 1911), an academic meeting composed of jurists, psychologists, and physicists was held in Göttingen.
Therefore, those who had gathered there were all people highly skilled in meticulous observation.
In that town, as if a carnival festival were in full swing, suddenly—amidst this scholarly gathering—the door was thrown open, and a clown clad in gaudy attire burst in like a madman.
When they looked, a black man came chasing after him from behind, pistol in hand.
In the middle of the hall, they took turns hurling terrifying words at each other, but soon after the clown collapsed abruptly onto the floor, the black man leaped upon him.
And then, there was a bang—the sound of a pistol.
And then, in an instant, they both left the room as if erased.
The entire event did not even take twenty seconds.
People were, of course, extremely surprised.
Apart from the chairman, no one had realized that those words and actions had been rehearsed beforehand or that the scene had been photographed.
Thus, it seemed perfectly natural that the chairman, stating this would eventually become a matter for the courts, requested each member to write an accurate record of events.
(Omitted here are details showing how error-filled their records were, with percentages provided.) Only four out of forty correctly stated that the black man had nothing on his head; others wrote that he wore bowler hats or silk hats—such was the state of their accounts.
As for his clothing, some said it was red, others brown; some claimed stripes, others coffee-colored—a multitude of varying hues were described for him.
However, the black man was actually wearing white pants, a black jacket, and a large red necktie.
(Omitted)

“As Münsterberg so astutely exposed,” Akechi began.
“Human observation and human memory are truly unreliable things.”
“Even scholars such as those in this example were unable to discern the color of clothing.”
“Is it unreasonable for me to think those students misperceived the kimono’s color that night?”
“They might have seen someone.”
“But that person couldn’t have been wearing vertically striped garments.”
“Of course, it wasn’t me.”
“Your deduction about spotting a striped yukata through latticework gaps was clever—too clever by half.”
“At the very least, rather than clinging to coincidental matches, won’t you trust my innocence?”
“Now—about the man who used Asahiya’s restroom.”
“On this point, I initially shared your view.”
“I believed no escape route existed beyond that soba shop.”
“But when I investigated myself, my conclusions regrettably opposed yours.”
“In truth, no such man ever borrowed their restroom.”

As the reader had likely already noticed, Akechi was attempting to prove his own innocence by denying the witnesses' statements, rejecting any criminal fingerprints, and even refuting the existence of an escape route—but didn't this simultaneously amount to denying the crime itself?
I couldn't comprehend what he was thinking at all.

"So, do you have any leads on the culprit?"

"I do."
He answered while rumpling his already disheveled hair.
"My approach differs slightly from yours."
"Physical evidence can be manipulated through interpretive methods."
"The pinnacle of detective work lies in psychologically penetrating the deepest recesses of human hearts."
"But this ultimately depends on the detective's own capabilities."
"In any case, I chose to prioritize that dimension this time."

“The first thing that caught my attention was the fresh wounds covering the bookstore owner’s wife’s entire body. Then before long, I discovered that the soba shop owner’s wife bore similar injuries. You must already know this. Yet their husbands hardly seemed like violent men. Both the bookstore owner and soba shop owner appeared gentle and reasonable by nature. I couldn’t help suspecting some hidden secret lay beneath this contradiction. So first I confronted the bookstore owner to extract that secret from him. Being acquainted with his deceased wife made him lower his guard somewhat, allowing relatively smooth progress. Through this, I uncovered a peculiar fact. However, matters proved more difficult with the soba shop owner—though unassuming in appearance, he was remarkably resolute, making it quite taxing to elicit information. Still, through a particular method I succeeded admirably.”

“You’re aware that psychological association tests have begun being applied to criminal investigations?”
“That method where you give numerous simple stimulus words and measure the speed of a suspect’s mental associations.”
“But I believe it needn’t be limited to basic words like ‘dog,’ ‘house,’ or ‘river’ as psychologists insist—nor does it always require chronoscopes.”
“For those who’ve grasped association diagnosis’s essence, such formalities become unnecessary.”
“Consider how famed judges and detectives unconsciously employed this psychological method through innate genius alone—long before modern psychology’s development.”
“Ōoka Echizen-no-kami was certainly one such man.”
“In fiction—take Poe’s *The Murders in the Rue Morgue*, where Dupin discerns his friend’s thoughts through bodily movements alone.”
“Doyle imitated this too—having Holmes make similar deductions in *The Resident Patient*—all forms of association diagnosis.”
“Psychologists’ mechanical methods merely compensate for ordinary minds lacking such innate insight.”
“I digress—but in that spirit, I conducted an association diagnosis on the soba shop owner.”
“I engaged him in varied conversations.”
“All utterly trivial chatter.”
“Then analyzed his psychological reactions.”
“But this involves delicate mental states and considerable complexity—details I’ll reserve for later. Regardless, it led me to one certainty.”
“In short—I’ve identified the culprit.”

“However, there isn’t a single piece of physical evidence.”
“So I can’t exactly go to the police.”
“Even if I did file a complaint, they likely wouldn’t take it up for me.”
“Moreover, another reason I’m standing by with my hands tied despite knowing the culprit is that there was no malice whatsoever in this crime.”
“It may sound strange, but this murder was committed with mutual consent between culprit and victim.”
“No—or rather, it might have been carried out at the victim’s own wish.”

I tried letting my imagination run wild, but I simply couldn't fathom what he was thinking. Forgetting even to feel ashamed of my own failure, I listened intently to this strange reasoning of his.

"So according to my deductions," he continued, "the murderer is none other than the proprietor of Asahiya. He was referring to that man who borrowed the restroom to obscure evidence of his crime—though mind you, that alibi wasn't his invention at all."

Akechi ran a hand through his disheveled hair. "The fault lies with us. By asking whether there'd been such a man—whether from you or me—we practically put the idea in his head. What's more, he'd mistaken us for police detectives."

"But why commit murder?" His voice dropped lower. "...This case has shown me—with brutal clarity—the horrific secrets festering beneath society's placid surface. Things that belong solely to the realm of nightmares."

The owner of Asahiya was a cruel sadist descended from the lineage of the Marquis de Sade—and what a twist of fate—he discovered a female masochist just one house over in the neighboring building.
The bookstore owner’s wife was a masochist no less than he.
And so, with the cunning peculiar to such afflicted individuals, they carried on their illicit affair without being discovered by anyone.
“…You grasp what I meant by a consensual murder now… Until recently, they had each barely sated their pathological desires through their legitimate spouses.”
“The fresh wounds found on both the Bookstore Owner’s Wife and Asahiya’s Wife stand as evidence of this.”
“Yet needless to say, they remained unsatisfied.”
“Thus when they discovered each other—the very counterparts they had been seeking—right across their doorsteps, one can scarcely doubt how swiftly an understanding formed between them.”
“Yet this outcome proved a twist of fate taken to extremes.”
“Through the compounding of their passive and active impulses, their deranged acts grew ever more intense.”
“And so on that night, they brought about this incident—one they themselves had never desired…”

I shuddered involuntarily at Akechi's uncanny conclusion.
What manner of case was this!

At that moment, the mistress of the tobacco shop downstairs brought the evening paper. Akechi took it and was looking through the society section when he let out a soft sigh and spoke.

“Ah, it seems he finally could no longer endure it and turned himself in.”
“What a strange coincidence.”
“To think we would come across such a report just as we were discussing that very matter.”

I looked at the spot he was pointing at. There, in small print, a brief article of some ten lines reported that the soba shop owner had turned himself in.