Hindsight

Back aboard the cruise ship, Takahashi Ren and the other two returned to their room.

After changing clothes, the three sat on their respective beds.

"So," Ishida said, "what exactly happened with our class? Why did we only get 120 points?"

"I'd like to know too." Toba Shigeru leaned against the headboard, his hands behind his head. "What exactly did Katsuragi do?"

"Why don't we work through it together?"

Toba Shigeru and Ishida exchanged a glance, then both leaned toward Takahashi Ren.

"You already have an idea?" Ishida asked.

"More or less," Takahashi Ren said. "First, how many points did our class start with?"

"After the 30-point deduction for Sakayanagi's absence, 270," Ishida answered.

"Right. We had 120 left at the end, which means we lost 150 points."

"Yeah." Toba Shigeru and Ishida nodded.

"No one in our class broke any rules this time," Takahashi Ren said slowly. "The only part where we could lose points was the final leader-guessing round."

"Now I remember." Toba Shigeru caught on quickly and immediately picked up the thread. "Each wrong guess at another class's leader cost 50 points, and if another class correctly guessed our leader, that cost us 50 points too."

"Exactly. We can be certain that at least one class correctly guessed our leader. And no one correctly guessed Class D's leader."

"Wait, I'm having trouble keeping up."

Ishida rubbed his temples, barely managing to sort out his jumbled thoughts. "Even so, did Katsuragi really not guess a single leader correctly? And we occupied three spots. Where did the bonus points for those go?"

"Because the rules said that once a leader was identified, all the bonus points their class had accumulated would be reset to zero."

Toba Shigeru explained, "And the 50 points earned by correctly guessing another class's leader counted as bonus points too."

"That makes sense." Takahashi Ren agreed with that explanation as well.

"Oh, so that's how it worked." Ishida understood at last.

"What I can't understand is why Katsuragi would try to guess the other classes' leaders." Toba Shigeru frowned. "With how cautious he is, he'd never touch anything he wasn't sure about."

"That's where the problem lies. Katsuragi wanted to score a major achievement in this Uninhabited Island Exam while Sakayanagi was absent. At a time like that, if someone promised to provide him with information about the other classes' leaders..."

"Was that person Ryuuen?" Toba Shigeru blurted out.

"Yes."

"You're saying Ryuuen and Katsuragi also made a private deal about guessing the leaders?"

"It's only speculation, but it's very likely."

"No, that doesn't add up. I saw the form Katsuragi submitted."

Ishida furrowed his brow, as though he had spotted a hole in the argument. "He wrote down the names of Class C's and Class D's leaders, but left out Class B. If he really cooperated with Ryuuen on this, why would he include Class C?"

Toba Shigeru glanced at him, a hint of exasperation in his voice. "Ishida, you're too naive."

"Cooperation is one thing, but it doesn't make the rivalry between the two classes disappear. If that contract didn't explicitly state in black and white that neither side could write down their partner's leader, Class C could do it too."

He paused, then added, "But since both Class C's and Class A's leaders were correctly guessed, we have no way of knowing how many bonus points they earned."

"Wait." Ishida couldn't help interrupting. "Even if Ryuuen really could get information on the other classes' leaders, we're talking about Katsuragi here. How could he possibly take Ryuuen's word for it?"

"Of course he wouldn't," Takahashi Ren picked up. "So Ryuuen had to produce something tangible and let him see the evidence for himself."

"Wouldn't... wouldn't that be even harder to pull off?"

"But you saw what happened-Katsuragi did believe him. Whatever methods he used, Ryuuen got his hands on tangible evidence. Hard or not, he pulled it off."

"Unfortunately, Class D completely overturned their plan in the end," Toba Shigeru said.

"Then how exactly did Class D do it? Based on what we just worked out, Katsuragi would never have written down Class D's leader's name without seeing solid proof."

"That is a question." Toba Shigeru turned to Takahashi Ren, who sat silently beside them. "Takahashi, what do you think?"

"There was a rule in the guidebook," Takahashi Ren began unhurriedly. "Leaders cannot be changed without a valid reason."

"Was there?" Toba Shigeru scratched his head, looking a little embarrassed. "The teacher read out such a long list back then that I've forgotten all of it."

"There was." Realization dawned on Ishida, and he lightly slapped his thigh. "So Class D most likely used some valid reason to change leaders midway through. That would explain everything."

"Exactly."

Toba Shigeru summed it up. "So, Class A guessed Class D's leader wrong and lost 50 points. Class D and Class C both correctly guessed our leader, costing us another 50 points each. That makes 150 points in total."

"But we can't rule out Class B correctly guessing our leader too, can we?" Ishida asked.

"I checked that," Takahashi Ren said. "I asked a friend in Class B, and she said Class B didn't guess any class's leader."

Ishida froze, then frowned even harder. "I can understand Class C, but how did Class D find out who our leader was?"

Takahashi Ren fell silent for a moment, then shook his head. "I don't know the answer to that either."

"Unless Class D lets it slip, there's no way to know, is there?"

Toba Shigeru patted Takahashi Ren's shoulder, his tone sincere. "It's fine. Figuring out this much is already impressive. If it were just Ishida and me, we probably wouldn't even know where to start."

"I really can't argue with that."

Hearing that, Takahashi Ren smiled. "It's just hindsight. Figuring all this out during the exam would have been impressive."

"You're being modest." Toba Shigeru was the first to object.

"Exactly," Ishida chimed in.

"I mean it," Takahashi Ren said frankly. "You two were helping too, weren't you? How could I have worked through it so smoothly on my own?"

"That's true." Toba Shigeru grinned and held up three fingers. "I contributed at least a third."

"Most of that was asking questions," Ishida took a jab at him.

"Weren't you doing the same?"

"I wasn't counting my questions as a contribution."

Toba Shigeru's eyes widened. "Ishida, you're picking a fight on purpose, aren't you?"

"I'm just telling it like it is."

"I'm telling you, I've put up with you for a long time, and I'm not putting up with you anymore."

"What a coincidence. Neither am I."

Watching the two clowns in front of him hold a lightweight sumo match, Takahashi Ren pressed a hand to his forehead and sighed.