A faint, hurried breath escaped from the mouth of a boy with bright orange hair.
"Huff…"
He wore a plain white T-shirt, a pair of gym shorts, and volleyball shoes that had clearly seen better days.
Thud! Thud! Thud!
Thud! Thud! Thud!
In an instant, three different impacts echoed, the sound of a volleyball striking his palm, then the wall, then the ground, over and over again in a seamless rhythm.
For the past two years, even without teammates to practice with, even when he didn't have enough players to form a team, even when there wasn't anyone to toss the ball for his spikes,
Hinata Shoyo never stopped practicing.
He continued his solo training, juggling the ball with his forearms in place or spiking and serving against the wall, endlessly, tirelessly.
Among his three childhood friends, whenever he caught one of them free, he would drag them out to help toss the ball for his spikes, no matter how much they protested.
This continued until their arms turned red and swollen from the ball's impact, sometimes even bruised beneath the skin.
But that day…
Hinata Shoyo's monotonous, routine life changed ever so slightly.
From behind him came a calm yet powerful voice.
"Do you like volleyball?"
Hinata froze.
Just like always, he was wearing his usual white T-shirt and sports shorts, practicing alone against the same wall he had struck thousands of times after school.
But…
Seeing his dazed reaction, as if he hadn't quite processed the question, Ichinose Guren patted the volleyball he had brought from school and smiled.
He repeated, slowly this time:
"You… like volleyball too, right?"
Guren's face showed no curiosity, no hesitation, only certainty. His tone carried conviction, as though he were declaring an undeniable truth.
As if to say: "Kid, you're definitely a die-hard volleyball maniac, aren't you?"
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Gym – Shower Room
"Hey, hey! Guren!"
Hinata's energy seemed endless,
even after finishing an intense, high-level training session.
It was a specialized routine designed by Ichinose Guren himself: ATP-focused functional training combined with growth exercises to help boost height.
After a short stretching and foam-rolling session in the rest area, Hinata entered the showers, already back to full power.
Meanwhile, Yudai Hyakuzawa, whose height and build far exceeded Hinata's, sat silently on a larger stool, washing off while catching his breath.
Hinata, who had been yelping from the cold water just moments ago, recovered quickly and began circling Guren with endless curiosity.
"Do we really not have to run? Isn't aerobic exercise the best endurance training?"
He asked cheerfully, scrubbing himself on his small stool like an overexcited kid.
Guren, hair drooping slightly over his eyes, gave the naked Little Giant a mildly disgusted glance, subtly shifting a step away, then returned to washing his hair.
Once the foam in his hair was rinsed away with cold water, he finally spoke:
"High-intensity exercise lasting over a minute is what suits aerobic training.
Sports like volleyball, basketball, and soccer rely on interval bursts, not continuous activity.
For movements lasting under ten seconds, the body relies on the phosphagen system.
From ten to forty seconds, it switches to fast glycolysis for energy.
Only after around a minute does the aerobic system take over."
Hinata blinked. "Ten seconds… phosphagen… glycolysis… aerobic…"
Seeing the boy's eyes already spinning in confusion, Guren sighed. He was used to this, the little academic disaster drowning in scientific terms again.
He clapped his hands to snap Hinata out of it.
"Well, you do need some cardio to build endurance. Just run about three to five kilometers at a moderate pace, that's plenty."
Ruffling the orange hair on Hinata's head, he added with a smile:
"Finish your shower, get some rest, and remember to eat the nutrition plan I made for you.
Eat well, sleep well, that's how you grow taller."
The moment he mentioned growing taller, Hinata's dazed eyes lit up like stars.
"Yeah! Alright! I'll finish washing up super fast, then eat and sleep right away!"
His fighting spirit reignited instantly, almost visible like a blazing aura.
As he hurriedly rinsed off, he muttered to himself between breaths,
I'll grow taller!
I'll become a giant!
Step by step, I'll reach the top!
I'll be the highest!
Watching the easily fired-up Hinata, Guren let out a quiet sigh.
"That's the charm of idiots, huh… they ignite so easily."
He rubbed his chin thoughtfully.
"In the original timeline, this guy only hit around… 172 cm as an adult, right?"
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Note: The body burns energy in different ways: super short moves use the phosphagen system, 10–40 second bursts rely on fast glycolysis, and after a minute, the aerobic system takes over. Basically, spikes = instant energy, rallies = quick burn, long matches = stamina.