"I'm unpredictable, right?"
Riku said proudly.
"True," Yuki smiled wryly. "Never know what you'll do."
"Is that a compliment?"
Aoi interjected. "Information-theoretically, a high-entropy state."
"Entropy?" Yuki asked.
"A measure of uncertainty. The less predictable, the higher the entropy."
Riku showed interest. "So I'm a high-entropy person?"
"Could say that. Your next action is hard to predict."
"Is that good or bad?"
Aoi thought. "Depends on context. Troublesome when predictability is needed. But a strength when creativity is required."
Yuki understood. "Not suited for routine work but good for idea generation?"
"Exactly. Low entropy brings stability, high entropy brings diversity."
Riku laughed. "So I'm in charge of diversity."
"But," Aoi continued, "being completely random also lacks information."
"Huh? Even though it's unpredictable?"
"For example, white noise. Completely random and unpredictable. But you can't extract meaningful information from it."
Yuki pondered. "So just being chaotic isn't enough?"
"Right. Unpredictability with moderate structure produces interesting information."
Riku asked seriously. "Unpredictability with structure?"
"For example, music. Completely repeating melody is boring. But completely random sounds aren't music either."
"Ah, balance of moderate variation and pattern."
"Exactly. There's an optimal entropy level."
Yuki wrote in her notebook. "Too low is boring, too high is chaos."
"Beautifully summarized," Aoi smiled.
Riku suddenly said. "So human relationships are the same?"
"Interesting perspective. Explain."
"Identical conversation every day is boring. But completely unpredictable people are tiring."
"Right. Balance of moderate predictability and moderate surprise is comfortable."
Yuki empathized. "Coexistence of security and freshness."
"Exactly. The tradeoff between redundancy and novelty in information theory."
Riku thought. "Am I unbalanced?"
Aoi laughed. "A bit high-entropy leaning. But that's also your charm."
"Because unpredictable means never boring to be with?"
"Could say that. Though I'd like a bit more predictability in important situations."
Yuki interrupted. "Like during exam period."
"Exactly," Riku scratched his head.
Aoi organized. "Entropy indicates potential information value. High entropy means more information gained from observation."
"So observing me yields lots of information?"
"Theoretically yes. Because behavioral patterns are unreadable, each action carries new information."
Yuki laughed. "Studying Riku as a research subject would yield interesting data."
"Stop it," Riku was embarrassed.
"But," Aoi said seriously, "understanding the value of unpredictability is important."
"Why?"
"A completely predictable world has no information. No surprise. No growth."
Yuki nodded. "Because there's uncertainty, there's something to learn."
"Yes. Entropy is the driving force of learning."
Riku looked outside. "Unpredictability makes it interesting. I'll make that my motto."
"Good motto. Just in moderation."
The three laughed. The world has value to live in because it has moderate entropy.