Chapter 5: A Curious Pulse

It was the kind of morning that felt like it didn’t belong to April — bright but chilly, where the wind moved gently through the open classroom windows and played with papers that weren’t weighed down.

Yasu sat at his desk, back row as always, elbow on the surface, cheek resting lazily against his palm. The world outside the window was far more interesting than anything inside the room — until she walked in.

Hoshiko-sensei.

There was something about the way she entered that commanded attention. Not with authority — not like the math teacher who always yelled — but with presence. Quiet confidence. That, and the way her skirt hugged her hips as she walked to the front of the class didn’t help the distracted thoughts in the minds of more than a few boys.

“Good morning, everyone,” she said, voice bright, though her eyes looked just a little too tired, as if she’d stayed up late doing something interesting — or mischievous. “Today’s lesson is about the circulatory system. I hope you all came prepared… because this topic has heart.”

A collective groan passed through the class.

Hoshiko clutched her chest in mock pain. “Tough crowd,” she sighed, then shot a glance at the back. “Yasu-kun, you’re unusually quiet today. Everything alright?”

He blinked at her. “I’m always quiet.”

A smirk curved her lips. “Touché.”

She began the lesson with her usual rhythm, pacing slowly between desks as she spoke, drawing diagrams of the heart on the whiteboard. She had a way of explaining things that felt more like storytelling than teaching — even when she was talking about blood flow and atrial valves.

“Now,” she said, pointing her marker like a wand, “can anyone tell me what causes the heart to beat faster?”

A hand went up from a girl in the front. “Exercise?”

“Correct,” Hoshiko nodded. “What else?”

Another hand. “Fear?”

“Right again.”

Then, without turning around, she added with a slight grin in her voice, “Attraction too. Sometimes, it beats faster when someone walks into the room and you can’t figure out why they’re suddenly more interesting than your biology notes.”

Laughter erupted.

Yasu didn’t laugh.

He just stared at the back of her head, face unreadable.

—

After class ended and the students rushed out for lunch, Yasu remained behind. As usual.

He pretended to pack slowly. But in truth, he was waiting.

“You’re going to wear out that seat one day,” came Hoshiko’s voice, casual, as she stacked papers on her desk. “I might need to rename it after you.”

“I didn’t realize desks could be memorialized.”

She leaned over the edge of her desk, chin resting on her palm. “Anything can be special if someone sits in it long enough.”

He didn’t respond. But he didn’t leave either.

There was a moment of quiet. Not awkward — just charged.

Hoshiko’s eyes flicked toward him. “Do you ever consider joining a club, Yasu-kun?”

“No.”

“Why not?”

“Too many people.”

She laughed. “What if I told you the science prep room is technically not a club, but I could always use a helper after school?”

Yasu looked at her, hesitant. “Is that allowed?”

She leaned forward slightly, voice dropping. “Breaking small rules is my specialty.”

“…You’re not supposed to say that out loud.”

“Which makes it more fun, doesn’t it?”

There it was again — the playful glint in her eyes. The line between teacher and teasing adult blurred just enough to be confusing. 

She walked over to the lab shelf, checking the glass slides for the next experiment. “Honestly, I just thought it might be nice if you weren’t always by yourself after the bell. You’re interesting company, even if you only speak in one-word sentences.”

“…I speak more than that.”

“Oh?” She turned, smiling. “Say five words, then. Right now. Go on.”

He thought for a moment.

“You… are… a strange woman.”

She clutched her heart in mock offense. “Yasu-kun, I’m wounded. Deeply. Right in the left ventricle.”

He gave a small exhale.

“Anyway,” she said, moving back to her desk, “think about it. It’s not a club. Just… you helping me after school sometimes. No commitment. No pressure."

“…Fine,” he said after a long pause. “Just sometimes.”

Her smile turned genuine. “Good. I’ll make sure to stock up on snacks .”

As he turned to leave, she called out one last time:

“Oh — and don’t worry, Yasu-kun. I won’t tell anyone you’re secretly sweet.”

He stopped at the door. “You’re imagining things.”

“Am I?” she replied, already scribbling something onto her lesson planner. “That must be my wild, unscientific heart talking.”

He didn’t look back.

But his ears were red.