Not a detective

For example—

"Takahiro Uemura was not actually at home at the time. His twin brother was at home. He had gone missing outside."

“Yoshihiko Arimura, his family lied, or they wished he would disappear, so they are not sure if he went out.”

"Tetsuji Sugino, his family actually has a secret passage leading to the outside world, um... maybe it's a ninja family."

Chizuko erased a corner of the three circles, revealing a small opening in the [Secret Room].

"Of course, these are just my wild thoughts, but Asakawa-kun, have you noticed a problem?"

"……Um."

Asakawa Riku frowned; his expression was not good.

The three examples she mentioned are already incredibly absurd coincidences, let alone happening simultaneously. But even with such a small probability, the other four... the four locked rooms still exist.

So that's how it is. The real difficulty in this case lies not in the "locked room kidnapping," nor in the mystery itself.

It's not about quantity!

The disappearance of seven students is too many... Once it accumulates, quantitative change will lead to qualitative change.

One escape room may have a loophole, but it's almost impossible for seven escape rooms to have problems at the same time!

Spring of the Earth Spider: Chapter Fifteen - Insignificant Grammatical Errors

The real difficulty in the murder-foreshadowing love letter case is not the method itself.

It lies not in the quantity, but in the scale of the crimes.

Seven victims, seven crime scenes, seven locked rooms – this not only requires a large criminal organization, but also gives the locked rooms an incredible air of mystery.

How can we take these seven students away without them noticing?

"I'm afraid there's no other way but to disappear into the shadows."

Chizuko seemed to see through Asakawa Riku's confusion and said with a smile, "That's why I said it was a crime committed by a yokai."

"Wait, I need to interrupt." Asakawa Riku suddenly found a problem: "If the day I received the love letter was the first day of school, which was a Monday, does seven days later mean Sunday?"

"Huh? What do you mean?"

Chizuko seemed surprised by his words and paused for a moment.

"If today is Monday, I should call Sunday 'the seventh day' (七日目), because I'll kill you on the seventh day."

Rikuya Asakawa picked up the chalk and wrote the word on the blackboard, then started a new line: "But the culprit wrote 'seven days later'. Killing you in seven days, as I understand it, might be next Monday, or some day after next week, in short, it would be some day after the seventh day ends. How could it be a Sunday?"

He had lived here for sixteen years, so his Japanese was quite good.

After hearing this, Chizuko rested her fingers on her chin and fell into deep thought.

Clearly, this was the first time she had noticed this blind spot.

"Could it be that you've misremembered, Asakawa-kun? Maybe the culprit wrote 'the seventh day'?"

"...I'll find it for you."

Asakawa Riku certainly didn't think he had misremembered. Although he was indifferent to the incident, he wouldn't be so confused as to get a few words mixed up.

He rummaged through his schoolbag, turning it upside down and almost emptying it, but still couldn't find the letter.

"what happened……"

"It seems the letters have also disappeared." Chizuko also looked surprised.

For the first time, Asakawa Riku sensed something strange. It seemed impossible for anything to approach him silently and take the items from his backpack.

He carefully checked his wallet, and thankfully, the cash was still there.

"Oh, right... I didn't just suddenly remember this. I only noticed it after seeing your notes, President!"

Suddenly realizing what was happening, Asakawa Riku pointed at Chizuko: "The original text of the letter was also copied into your notebook... I will kill you in seven days."

"what."

Chizuko slightly opened her mouth, took out the small notebook from her pocket again, opened it, and indeed, it contained the exact same words.

The love letter read: I will kill you in seven days.

It was this sentence that made Asakawa Riku discover the loophole.

"Could I have misheard? After all, I gathered this information from rumors, so it might not be entirely accurate."

She began to doubt herself.

"So, do you have a photo of that incident from a year ago? Any one of the seven love letters will do."

Asakawa Riku noticed that the investigation notebook contained a lot of supplementary materials, such as newspaper clippings and on-site inspection photos, but there were no photos of love letters: "If there were, we could confirm it by comparing them."

Chizuko shook her head helplessly: "That's police evidence. I don't have the guts to do that. Besides... if your love letter was vanished, their love letters might have disappeared long ago too."

Silence fell over the room; everyone was at a loss.

Chizuko suddenly stood up, tiptoed, and used the blackboard eraser to erase the two lines written by Asakawa Riku, then covered them with new content:

"There are three possibilities."

"First, the distinction between 'the seventh day' and 'seven days later' wasn't strictly defined. The prisoner just wrote it down casually without paying much attention."

"Secondly, the perpetrator was aware of this and did it intentionally. He was worried that the victim would be on guard in advance by announcing the love letter, so he took advantage of the wrong time."

"Third, the perpetrator did it on purpose. I've been wondering why they gave advance notice, and now I think it might have been to deliberately trap the search in such a meaningless mental trap."

She wrote three keywords on the blackboard: "meaninglessness theory," "time difference theory," and "interference with the search theory."

Then, turning to her, she said, "But, Asakawa-san, I don't think either of these explanations will be of much help in finding the culprit. Getting hung up on this will only waste time."

Chizuko-senpai is right, it's just a simple grammatical error, and the culprit might not even have noticed it.

Even if there are abnormalities, so what... It's impossible to find the culprit based on that, it's a bit nitpicky.

But Asakawa Riku still felt something was wrong.

Of the three theories, the first is that this "murder warning love letter" is a very important thing. If the criminal decides to deliver this warning, it is like a notice from the Phantom Thieves. It must be written with a sense of ritual, and the wording must be carefully considered with 200% focus. Especially the most crucial time of the crime, it is impossible to just casually brush it off.

Secondly, since the criminal gave a warning, he couldn't possibly be worried that the warning would alert the victim. If that were the case, there would have been no need to alert the victim in the first place. Judging from the criminal's lawless nature, he wanted to challenge authority and even succeeded. Such a person would never resort to tricks like time difference.

Thirdly, for the same reason as above, the prisoner is a confident and arrogant madman; he would never disrupt his important "announcement ritual" for the sake of merely interfering with the search.

Therefore, Asakawa Riku disagreed with none of the three explanations on the blackboard.

Seven days later, the seventh day... This time error is very likely the key to solving the problem.

That being said, he doesn't yet have enough evidence to refute Chizuko-senpai's judgment; it's all just speculation.

So, Asakawa Riku turned back from the side path and returned to the main road:

"President, may I ask you a question?"

"No need to be so polite, Asakawa-kun."

"I want to know, who exactly is the culprit in Chizuko's heart?"

"It's not that I asked you to be so impolite!"

Chizuko called out, but couldn't help laughing out loud.

This was indeed a counterattack. She had asked Asakawa Riku who he thought the culprit was, so Asakawa Riku was now asking him the same question in return.

He thought that since Chizuko-senpai had investigated for a whole year in advance, she must have her own reasoning.

Sure enough, she picked up the chalk again and wrote the last few words on the blackboard:

【Soil Spider】.

"Earth Spider?"

“Yes.” The girl turned her head, her smile elegant yet firm: “The culprit is Tsuchigumo.”

Earth Spider's Spring: Chapter Sixteen - The Prisoner is a Monster

What is a Tsuchigumo (earth spider)?

"A kind of monster."

"Is it a slang term for prisoners?"

"No, it's a monster, a monster in the literal sense. Only a monster can do something like this."

"……Well."

"That's a very rude expression, Asakawa-san."

After saying that, Chizuko got up, picked up her schoolbag, and prepared to leave.

Asakawa Riku was taken aback, wondering if he had said something to upset her, but she quickly pointed to the wall clock:

"It's time for club activities."

Six thirty-five.

Asakawa Riku recalled the school rules. The school stipulated that students should leave at 7:00 PM, but usually only sports clubs would finish at 7:00 PM, while general arts clubs would disband at 6:00 PM.

But he still felt there was more to say, especially during the crucial moments of explaining the killer:

"Could we extend the time by another half hour? I want to clarify the case today."

“No.” Chizuko shook her head, feeling that she was deliberately keeping me in suspense: “My home is far away, and my mother will worry if I go back too late.”

"President, this is a matter of life and death. I'm going to disappear in five days."

"Haven't you always been indifferent, Asakawa-san? Hahaha..."

Chizuko smiled and pushed open the door, leaving without pausing at all.

Only at the very end did she turn around and take one last look:

"I'm giving you some homework. Please research information about the [Tsuchigumo] before tomorrow afternoon."

...

The next day was fast-forwarded by Asakawa Riku.

Of course, this is a rhetorical device; he doesn't actually possess such superpowers.

Because I kept thinking about the "earth spider," I was always a bit absent-minded when doing other things. When I got home, I turned on the computer to search for it.

Thanks to the modern internet, he can find very detailed information without spending his precious living expenses to buy books at bookstores.

After organizing his notes into his phone, he quickly fell asleep.

The second day was also uneventful. High school life was not as colorful as I had imagined. Apart from the mystery club, it was just ordinary classes.

By the way, at noon, Chizuko-senpai brought a combination of "luncheon meat rice ball + Scottish soft-boiled egg + blanched bok choy + grass jelly matcha milk + strawberry", which I have to mention.

It was incredibly luxurious and delicious. Asakawa Riku was moved to tears and expressed his utter admiration for the president's culinary skills.

This is not your average Japanese bento box; it incorporates the styles of various dishes, and even includes a milk tea-like beverage and fresh fruit, making you wonder if it was a set meal brought from a family restaurant.

Asakawa Riku even felt that he hadn't spent enough, but Chizuko-senpai smiled and said: "Just make one more, that's enough."

An angel?

After eating and drinking to their hearts' content, with half of their lunch break still remaining, Asakawa Riku decided to chat about "Tsuchigumo," but was interrupted as soon as he opened his mouth.

"It's lunch break now. Please leave the case for club activities."

Chizuko righteously rejected his chat request, seemingly like a working person who didn't want to work during her rest time.

But when he's teasing us, he's especially like a devil.

She was lying on her side in the chair, maintaining an incredible balance while taking a nap, with her right hand under her head as a pillow. If she woke up, her head would definitely be numb.

If she were awake, she would definitely say that this balance was the result of the monster's help, Asakawa Riku thought.

But Chizuko-senpai lay there comfortably, the sparse sunlight filtered through the curtains illuminating the translucent fuzz on the girl's face, creating a striking contrast of light and shadow, like a cat.

The room was silent, with only the sound of their breathing.

Not wanting to disturb them, he quietly left the activity room.

...