Not a detective

Page 147

Unable to sense any supernatural presence, Asakawa Riku had no idea how terrifying the mystery club witch could be under that kind of "atmosphere." He chuckled and patted her on the shoulder:

"It's okay, no need to explain. Going to the student council is fine too, anyway, nobody participates in the mystery club activities anymore."

"...But I didn't expect you to be the challenger."

Kasahara had already figured out why Asakawa Riku came here.

The student council announced the five stages of the "Summit War" in advance, located in five different locations within the school building. Those who come here to talk to the students are mostly challengers.

Although there are still four days until the school festival, there are the most challengers today. If the location is not confirmed by Monday, the class booth may not have enough time to be set up and prepared.

Therefore, it must be completed today to give the other students in the class more time.

"I'm in charge of the first stage. But only one-tenth of the people who came here today will be able to pass it smoothly, okay?"

He said mysteriously, building up the atmosphere, "Should I secretly give you a break, and pretend you've already passed?"

Asakawa Riku narrowed his eyes and smiled:

"You... you've really changed a lot. You're only saying this because you know I'm not going to agree, right? Fine, I'm a man of my word. Bring it on!"

He would never give up his obsession with winning and fairness over such a trivial matter. Even if he knew it was an open conspiracy, he would still confront it head-on.

“Alright…” Kasahara smiled as well: “Then please step forward, Asakawa-san, and I’ll introduce you to him.”

"and many more."

Asakawa Riku abruptly changed the subject, stepping aside to pull out Shinonome Suetsuki beside him: "Let me introduce them first, this is the [Challenger]."

"Ok?"

Kasahara was stunned, seemingly not expecting this situation. He stared at Sueki for a long time, not even as tall as her.

"That's possible... but is this student also a student in Grade 11, Class B? What's their name?"

Call me Dongfeng.

"Dongyun Sueyue said abruptly, still with a sour face, seemingly still upset about what had just happened."

I don't know if she's been playing too much mahjong and has forgotten her own name, or if she hates that surname and doesn't want to say it here.

Surprisingly, Kasahara actually believed it: "Oh, Dongfeng-kun, let me explain the rules to you. Asakawa-kun, you can act as the referee to ensure the fairness of the rules."

"Okay."

Asakawa Riku was secretly delighted. He hadn't expected to overcome the most difficult hurdle so easily. As long as Higashion Suetsuki's identity wasn't exposed, things could proceed smoothly.

So Kasahara also stepped aside, making way for what was behind him—

"As you can see, these are the [items] we will use in the first level."

"There's nothing here..."

Asakawa Riku naturally questioned it. He glanced at it and saw that there was nothing on the stairs leading from the first floor to the corner of the first floor, let alone any props.

Kasahara smiled mysteriously: "It's stairs...that's right, the first game is climbing stairs."

"Isn't this a physical game?"

Asakawa Riku frowned: "I heard that the student council is preparing brain teasers. It shouldn't be something like having to run through a floor in one second, or running from top to bottom, right?"

He began to regret it. He should have known better than to reveal the challenger's identity so early, and he could have decided who to send based on the rules.

If it were a physical game, he would definitely have a greater advantage than Shinonome Suetsuki...

"No...no, no, no, what you're saying is way too exaggerated. Is it even possible for a human to do that..."

Kasahara was startled. He couldn't figure out if Asakawa Riku was joking, so he quickly explained, "Not only is that not the case, but I can guarantee that this is also a pure 'intellectual game'. It doesn't require any physical strength or speed. As long as you can successfully reach the next level, which is the platform at the corner, the challenger wins, even if it's slow."

"Oh." Asakawa Riku understood: "So, there are some special rules and conditions, right?"

"Yes."

Kasahara held out both hands: "Asakawa-kun, Touka-kun, did you play hopscotch when you were little?"

"Ah, is it one of those games where you draw alternating squares on the ground and then hop across them using one foot at a time?"

Asakawa Riku remembered, but not in this life, but in his memories of his past life.

"Yes, that's it."

At the same time, Kasahara also made a hand gesture, using the palm of his left hand as the floor and his other hand to make a shape.

When the index and middle fingers touch the ground with both feet, jump one step and retract one index finger; this is standing on one leg.

Take another step, and you land on both feet again.

It's surprising that the two countries have such similar childhood games. However, Asakawa Riku was too precocious after transmigrating, so he didn't actually play these games with his friends when he was a child.

"I think I understand the rules... but what does that have to do with climbing stairs?"

"I combined the two games slightly—and called it 'Staircase Jumping'."

Zashiki-warashi no Autumn: Chapter Seven - Landmine Jumping Down the Stairs

“The rules are as follows:”

"The challengers are divided into two forms: standing on one leg and standing on two legs. Of course, in reality, they must also maintain this form."

"At the beginning of the game, challengers need to start the game in a 'two-legged' position. After each time they stop on the steps, they must switch to a 'one-legged' position until the next stop."

"The condition for passing through is to reach the next level, which is the corner platform. There are 12 steps in total. Can you confirm the number?"

"...Asakawa-kun, you said we don't need to confirm? Okay then, it's the 12th floor anyway, you can tell at a glance, and you can do mental calculations too."

"In addition to that, there is an extra condition: you must be standing on both feet the moment you reach the platform to win, because only standing on both feet is considered stable."

...

"So, you jump up like this: two feet, one foot, two feet, one foot?"

Asakawa Riku calculated that on the ground, he would use two feet; on the first level, one foot; on the second level, two feet; on the third level, one foot... and so on. When he reached the 12th level, he would use two feet.

"The quantity is correct, but isn't this still a physical game?"

It's just a matter of maintaining the rhythm of jumping on one or two feet, and there are only twelve floors in total. Even for ordinary people, it's not difficult, even if you're not Riku Asakawa.

This game shouldn't be able to maintain a 90% elimination rate.

Kasahara smiled, gesturing for him not to rush: "Because the rules haven't been fully explained yet, please allow me to continue—"

...

"Challengers must go up each time; they cannot stay in one place, nor can they go downstairs on their own initiative."

"There is no limit to the number of floors a challenger can jump in one go. Even if they jump several floors in a row, it is still considered as one step."

"Yes, you should soon realize that although there are no rules, you can't go straight to the top in one step, because that would require you to be on one leg, and being on one leg doesn't meet the requirements for passing the level. Therefore, challengers have to take a break halfway through and choose to stay on one of the 1-12 floors to make the next step meet the requirements for passing the level."

"But even so, it was still too easy to get through, so as the organizer, I set a limit. I planted mines on these stairs."

"Asakawa-kun... don't make such a scary face. Of course it's not real, it's just a game concept... Challengers can't go downstairs on their own, but if a challenger happens to be on the [mine staircase], they will be forced to descend three steps and must switch forms, because no one can stand on one leg after being blown up, right?"

"Furthermore, challengers do not have unlimited chances. Each step is considered one round, and if they fail to reach the finish line within three rounds, the challenge is considered a failure."

...

"So this game is—"

Shinonome Suezuki finally broke the silence, her lazy eyes opening as if the game had piqued her interest:

"Find the correct [resting point] on the mine-strewn stairs, complete the form switch, and reach the top to succeed, right?"

"...That's right, a very accurate summary."

Kasahara paused for a moment, then nodded, looking at this unfamiliar classmate with newfound respect and becoming more wary: "It's a very simple game, it should only take about ten minutes to finish."

Conversely, Asakawa Riku still has some questions:

"It is indeed a very simple rule, I understand. But if we calculate it this way... this rule actually gives the challenger an advantage, and it's not fair to the organizer?"

There are three landmines scattered across the twelve steps.

The probability of stepping on it is only 25%. Even if you rely entirely on luck, you might not be able to step on it. Once the challenger completes the "switching feet" maneuver, the next step will take them straight to the finish line, and they will win.

Even if you're unlucky, the penalty for stepping on something isn't severe; it's just dropping three floors, which is insignificant for challengers who can climb countless floors at once.

The most severe penalty is to switch back to bipedalism, wasting a turn, and having to spend another turn to find a suitable foothold.

Under these rules, the organizers are at a serious disadvantage; they lose if the challenger manages to safely switch feet even once.

The time limit of three rounds is not particularly strict. Asakawa Riku did a quick calculation and found that it would take two rounds to clear the level, because one round is needed to switch to one leg.

In other words, the challenger has one chance to make a mistake; being hit by a landmine does not necessarily mean defeat.

Even if you're unlucky and get blown up by a landmine in the first round, which lowers your score, you've already eliminated one wrong answer. So next time you choose, you shouldn't make the wrong choice.

In other words, it's actually harder for the challenger to lose! They have to step on two landmines in a row and can't find a safe place to switch feet. They won't have enough time in the third round to pass the level.

The probability is roughly 25% for the first 12 out of 3, 18% for the second 11 out of 2, and a mere 4.5% for hitting the landmine twice in a row...

No ordinary person would be this unlucky!

"...You're not really going easy on me, are you? Can these rules really eliminate 90% of the challengers?"

Asakawa Riku looked at Kasahara with suspicion.

Kasahara shook his head and smiled: "Since I said not to hold back, of course I won't do that. Asakawa-kun, just like the 'Full Power Punch' you taught me, I only realized afterwards that it wasn't your full power punch. You could definitely do something even more powerful. It was because you anticipated my strength and threw my full power punch. This is telling me that even the weak can fight back with all their might. As long as it's a full-force counterattack, even the strong will suffer. So, this 'Landmine Jumping Stairs' game is also my full power."

Asakawa Riku paused for a moment: "What you said makes a lot of sense, but..."

Kasahara's words were very philosophical. Although they may not be what Asakawa Riku meant, they represent a correct and positive outlook on life.

But what does this have to do with the fact that the rules he proposed are unfair? Statistically and probabilistically, it's clearly easier for the challenger to win, isn't it?

"You care too much about numbers, Lu, that's why your mahjong skills are so terrible."

At that moment, Dongyun Sueyue, who was standing beside her, suddenly spoke. She smiled and spoke, her previous impatient expression gone:

"This isn't a game of probability, it's a game of psychology, am I right?"

Kasahara was on high alert when faced with her questioning.

For some reason, I suddenly felt a strange pressure. After pausing for a moment, I replied:

"Yes... Dongfeng is right. For the organizers, they need to understand the challenger's psychology, guess in advance which three steps the challenger will go to, and set up mines; for the challengers, they need to understand the organizers' psychology, avoid the mines set by the organizers, and find a safe place to switch feet to win... So, this is a game of psychological warfare."

Zashiki-warashi no Aki: Chapter 8 Psychological Games

"The rules have been clearly explained."

Kasahara coughed twice and got back to the point. He took out a piece of paper from his pocket and said, "To ensure fairness, I have written down the number of steps on which the landmines are placed beforehand, so you don't have to worry about me making things up. As for this piece of paper, you can give it to Asakawa-kun. As the referee, you can check if it is normal."

Asakawa Riku closed his eyes, took the paper, and put it in his pocket without peeking through the ink stains on the back or analyzing it by touch.

"I won't look. Otherwise, I might give this guy a secret signal to tell her where the landmines are."

He still holds a strong belief in fair competition and would not resort to such underhanded tactics.

"That's settled then. If Dongfeng steps on a landmine, I'll report it. Then, after the game, I'll get the note from Asakawa to confirm if it's real."

Kasahara said this, and Asakawa Rikuya nodded in agreement.

"Come on."

Although he still harbored doubts about those mysterious "psychological games," there was no turning back now that things had come to this, so he decided to entrust everything to Shinonome Suetsuki. Even if she didn't have the ability to truly predict the future and see which three floors Kasahara had placed his landmines on, her luck had always been good. Not to mention a 5% probability, she could even win hands with a probability far below 1%.

Will Shinonome Suetsuki step on two landmines in a row?

Impossible! On that day at the mahjong table, she didn't give Asakawa Riku a single chance to win. If Asakawa Riku didn't win by drawing the winning tile himself, he wouldn't even earn any money from her!

He gripped the other's hand tightly, his eyes silently declaring—no matter what, he would reach the summit.

Ignoring Asakawa Riku's sincere entrustment and trust, Suezuki suddenly raised his hand and said:

"Ah, although I am the challenger, he will be the one to jump the stairs."

"What are you doing..."

Asakawa Riku was taken aback.

Kasahara also seemed a little embarrassed: "Uh... Dongfeng-kun, the rules and challengers have already been determined. Isn't it a bit inappropriate to change the person now?"

"It's not about changing people... Well, just treat him as my puppet. I'll tell him which floor to go on, and he'll go on whichever floor I tell him to go on. He's just a slave, okay?"