In the world of professional volleyball, Rintarou Shimizu was a name spoken with awe.
Japan's national team captain. Three-time MVP of the World League. Nicknamed the Sky Emperor for his insane vertical, pinpoint accuracy, and legendary calm under pressure.
He had it all—fame, wealth, and a trophy case so full it needed its own room.
But all that meant nothing the moment he saw his younger sister's message.
Kiyoko:
"Nii-san… Can you come to Karasuno sometime? Our volleyball team… needs help. I think you're the only one who can help them."
Most people would've ignored a request like that. Not Rintarou.
Not when it came from Kiyoko—his little sister, the one person who grounded him in a world that constantly demanded more.
And not when it came from Karasuno High, the place that gave him everything.
---
One Week Later – Karasuno Gym
The familiar creak of the wooden floor greeted him as he stepped inside. The smell of old sweat and dust hit his nose.
Rintarou dropped his duffel bag and quietly observed.
Six boys were on court, clumsily doing receive drills. No proper rotations. No real structure.
But he didn't see failures. He saw potential.
He saw fire.
Just like the one he had back then.
"Oi! Who the hell are you?" one of the boys called out. A loud, lanky first-year with wild energy.
Before Rintarou could speak, a clipboard smacked the kid on the back of the head.
"Shut it, Tanaka," Kiyoko said flatly.
She turned to her brother. "Told you they're rough."
Rintarou smiled. "Rough is good. Rough means they haven't been polished wrong."
---
Later That Evening — Faculty Office
"I still think this is insane," the current PE coach mumbled. "You're a global athlete. Why here?"
Rintarou leaned back in his chair, arms crossed. "Because this place built me. Because my sister asked. And because the crows shouldn't have fallen this far."
The door creaked open, and an old man stepped in with a walking stick.
"Still dramatic, I see," the man grumbled.
Rintarou stood immediately and bowed. "Sensei."
Ikkei Ukai smirked. "You still remember your roots, good. Now, what's this nonsense about saving Karasuno?"
"You taught me everything," Rintarou said. "It's time I pass it on."
The old coach chuckled. "Then don't just teach them volleyball. Teach them how to want it."
Rintarou nodded. "That's the plan."
---
Two Weeks Later — Practice Day 1
The gym was transformed.
Fresh volleyballs. New nets. Clean jerseys. Upgraded floorboards.
Nutrition plans posted on the wall. Water coolers in every corner.
The team stood in shock.
"Where… did all this come from?" Daichi murmured.
Rintarou stood at the front, arms crossed. "You need tools to win. I've provided them. All I ask in return—"
He tossed a ball high into the air and caught it one-handed, eyes locked on each boy.
"—is everything you've got."
He handed out personalized journals. Each had their name, strengths, weaknesses, and daily training goals.
He'd been watching. Tracking. Planning.
They were stunned.
This wasn't a celebrity pretending to coach.
This was a leader who cared.
---
Outside the Gym — That Night
"Are you really going to stay here?" Kiyoko asked, voice quiet.
Rintarou looked up at the stars above their old school. "I'll leave when they no longer need me."
She gave a rare smile. "That might take a while."
"I hope so," he said.
"Why?"
"Because that means they're still growing."