It was another ordinary school day.
Sunlight spilled through the classroom windows.
The teacher at the front of the room was explaining the complicated relationships between characters in a chapter of the book, in a voice so even it was almost hypnotic.
The warm air and monotonous recitation made for an irresistible lullaby.
Kazehara Tetsu propped his chin on one hand, leaning his upper body against it, while his other hand idly twirled a pen.
His eyelids drooped, and his gaze wasn't fixed on the book. His mind was completely elsewhere.
His consciousness had long since drifted away from the classroom.
Just then, he felt a faint touch on the back of his neck, like a flying insect had accidentally bumped into him.
He paid it no mind, merely shifting his neck without thinking.
A few seconds later, the same sensation appeared in the same spot again.
This time, it struck a little harder, with the slightest impact.
Kazehara Tetsu's pen stopped twirling for a moment.
He didn't look back.
His posture didn't change at all. He still looked half-asleep.
But beneath his drooping eyelids, his gaze sharpened, and all traces of drowsiness vanished.
He could clearly make out the faintest rustling behind him, along with... the barely audible twang of an elastic band being stretched.
"Snap."
The third shot was more accurate than the first two.
A small paper pellet hit the rim of his ear dead-on with a soft crack, then dropped onto his shoulder.
Kazehara Tetsu finally moved.
Slowly, with the languid speed of a movie in slow motion, he turned his head toward the back of the classroom.
His movement was slight. He only turned his face enough to take in everything behind him from the corner of his eye.
Morishita Ai.
She was frozen in an utterly ridiculous pose, leaning forward with one hand raised high. Two fingers held the stretched elastic band while her other hand was just about to fish another "round" out of her pencil case.
When her somewhat scatterbrained eyes met Kazehara Tetsu's gaze, she froze like a cartoon character caught mid-motion.
The air between them seemed to stop for three seconds.
The next moment, Morishita Ai reacted with startling speed.
She snatched her hands back, shot upright, and placed them primly on her desk.
Her face turned toward the window. She even began whistling a tuneless, breathy little tune, wearing the innocent expression of someone who was "just looking at the scenery, and nothing happened."
Her acting was so over-the-top that anyone with a normal IQ could see right through it.
Kazehara Tetsu watched her performance without expression for a few seconds, then slowly turned back around.
He didn't pick up the paper pellet on the floor or pay any further attention to the sounds behind him.
He simply propped his chin up again and lowered his eyelids, as if everything that had just happened were an illusion and he were once more the student with no interest in class.
But Morishita Ai, sitting behind him, felt as if the air around her had suddenly dropped several degrees.
She cautiously glanced at Kazehara Tetsu's back, and for some reason, she felt a twinge of guilt.
She hunched her shoulders and finally settled down, quietly stuffing the "weapon"—the elastic band—into the deepest recesses of her desk.
"Ding-ding-ding—"
At long last, the lesson ended. The bell rang, releasing the tension in the classroom.
The students gathered in small groups, discussing where to get lunch or where to go hang out.
Kazehara Tetsu didn't move.
He stayed in the same position he'd held throughout class. Only after the voices around him gradually thinned and most of the students had left did he leisurely stretch and start packing up.
"Kazehara Tetsu!"
A loud voice rang out beside his desk.
He looked up and saw Morishita Ai standing there with her hands behind her back, leaning forward slightly. Her face was dead serious as she brought it close to his, her wide eyes fixed on him.
For some reason, looking at Morishita Ai's face left Kazehara Tetsu feeling strangely unsettled. She had the features of a sophisticated older-sister type, but with that earnest expression, she gave off a peculiar impression.
"Did you hear a strange sound during class?"
She asked with utmost seriousness, as if discussing a difficult academic question. "It was kind of like... like an invisible woodpecker tapping on the classroom walls over and over! 'Tap, tap, tap.' Do you think our school has some strange, secret stories nobody knows about?"
As she spoke, she mimed a woodpecker pecking at a tree with her finger, her performance remarkably lifelike.
Kazehara Tetsu watched her quietly.
He said nothing. He simply bent down and picked up the paper pellet that had fallen beside his chair.
He placed it on the desk and unfolded it layer by layer.
At its center was a pile of black eraser crumbs.
He pinched up the crumbs and held them before Morishita Ai's eyes, level with her gaze.
"Is this the 'invisible woodpecker' you were talking about?"
Morishita Ai stared at the crumb in front of her, the "evidence" swaying before her eyes.
Her brain seemed to freeze for two seconds. Then she clapped her hands and put on an exaggerated look of sudden realization.
"Ah! I remember now!"
Her voice rose sharply, drawing the attention of the few students still left in the classroom.
"Right, right! Kazehara Tetsu! I happen to have a question for you, one of the great mysteries of the century!"
She spoke so quickly that Kazehara Tetsu had no chance to interrupt or ask what she meant.
"Last night, I stayed up all night pondering the ultimate question, one that concerns human evolution and the fate of the universe!"
She spread her arms, her expression solemn and grave. "Why do humans need to sleep? It's a massive design flaw! Think about it—if humans didn't need to sleep, we'd have an extra eight hours every day! We could use those eight hours to study, work, invent, and create! Our civilization could advance at least twice as fast!"
She got swept up in her own grand vision, her eyes shining with boundless hope for the future.
Kazehara Tetsu looked at her as if she were an alien.
"But!"
Morishita Ai changed tack again. She leaned closer and lowered her voice. "After observing you, I discovered an anomaly that could overturn modern science!"
"And that anomaly is you, Kazehara Tetsu!"
She pointed her index finger at him, bringing it close to the tip of his nose. "You sleep in class, but you still get the only perfect score on the quiz! That completely contradicts the basic law of human society: 'Effort yields rewards'!"