The next day was normal, almost identical to the previous one, with only the classes and conversations changing.
During the break, Isagi sat once again with his soccer teammates, this time without any girls or his lazy friend, Kuze.
When the final bell rang, he grabbed his backpack and left school without any hurry.
The sun was already tilting in the sky, painting the busy streets in golden hues, while the warm late-afternoon breeze carried that familiar scent of the city.
When he got home, he dropped his backpack on the bed and quickly changed out of his uniform into light training clothes: a white T-shirt, athletic shorts, and a pair of sneakers.
Then, after informing his parents, he headed out again.
The subway wasn’t crowded at that hour.
Sitting down, with his headphones hanging unplugged around his neck, he rested his head against the glass and watched the reflections blend into the darkness of the tunnels.
He planned to take his first step that day…
When he finally got off at the station near the coast, the air changed.
The salty sea breeze filled his lungs, carrying with it the constant sound of waves crashing.
The walk to the beach was short, and soon the open horizon stretched before him, the sea shimmering under the last traces of sunlight, creating a breathtaking view.
A sight he had never experienced in his past life, one that drew a faint smile from his lips.
Still, he wasn’t there just to admire the beach and the sea.
There were few people around, since it was late afternoon, which was perfect for him.
He took off his sneakers and socks, leaving them near a rock.
“Let’s go…” Then he started running.
The sound of the waves matched his rhythm.
The wind hit his face—salty, refreshing.
Soon, he felt his muscles burning earlier than expected.
The resistance of the sand was cruel; it drained energy quickly, and within minutes he was already sweating.
Even so, he didn’t stop.
He clenched his teeth and stayed focused, thinking about how many players would give up on this because it was uncomfortable.
His heart pounded loudly, the air scraping his throat, but his eyes shone.
When his breath threatened to fail, he stopped just long enough to bend forward, rest his hands on his knees, and catch his breath, sweat dripping from his chin onto the sand.
Then he started running again, this time alternating directions, simulating sharp changes as if he were on the field.
Running straight was hard, but changing direction demanded even more.
The sand became an unpredictable enemy, and he had to adjust his balance every second.
The training continued like that until the sky truly began to darken.
The sunset had already dipped into the sea, and the first bluish tones of night painted the horizon.
Panting, Isagi finally stopped, dropping into a seated position on the damp sand near the water’s edge.
The sea slowly advanced, soaking his legs and cooling his heated skin.
He took a deep breath, watching the constant movement of the waves.
During class that day, he had come up with this idea.
Running on sand is one of the most efficient forms of training for an athlete because the ground doesn’t offer the same stability as asphalt or grass—part of the force you apply with your foot “sinks” instead of propelling you forward.
This means the muscles have to work much harder to generate the same movement.
For the legs, the effect is immediate: quadriceps, calves, glutes, and even the hip muscles are forced to contract more intensely, precisely because the ground doesn’t return energy.
In addition, since balance is constantly challenged, the stabilizing muscles—the deeper ones responsible for keeping the body steady—are also engaged all the time.
In soccer, this type of training has several direct advantages.
For example, since sand demands more force with each step, when returning to a normal field, the muscles feel lighter and more explosive, allowing quicker sprints and greater endurance in long runs.
Another point is the unstable nature of sand, which mimics situations of physical contact or uneven terrain on the field.
Training this way helps a player maintain stability even when being pushed or when needing to change direction suddenly.
And most importantly, the core and lower back work together with the legs to stabilize the body.
This translates into more powerful shots, firmer dribbling, and better protection against injuries.
And despite being exhausting, sand absorbs the impact of each step.
This allows for high-intensity training without putting as much strain on the knees and ankles, helping to prevent injuries.
In the end, running on sand creates a kind of “natural overload.” If a player gets used to performing well on terrain that drains energy with every movement, then when they return to grass—where the ground is firm and responsive—they gain more speed, power, and control than before.
He decided not to bring the ball yet because he wanted to get used to moving on the sand during the first week.
Isagi spent a few minutes sitting there, letting the sea cool his legs and clear his mind.
When he noticed it was already dark enough for the lights along the shore to begin turning on, he slowly stood up, brushing the sand off his body.
He picked up his sneakers and socks beside the rock and put them on without much haste.
Then he started walking toward the station.
The subway was emptier than before.
Upon entering the carriage, he found a free seat and sank into it, resting his head against the backrest.
The gentle vibration of the train, combined with his fatigue, almost made his eyes close completely.
The subway continued its route, stopping at station after station.
People got on and off, but to him, everything felt distant.
When the metallic voice announced his station, he stood up, adjusted his backpack on his shoulder, and stepped out.
The city air welcomed him again, but this time the warmth of late afternoon was gone, replaced by the calm of the night.
He walked along the illuminated streets until he reached home.
As soon as he opened the door, he was greeted by the aroma of freshly prepared dinner.
His parents looked at him from the kitchen, surprised by the time.
After greeting them, he sat at the table while his father turned off the living room television and joined them.
The food was simple: rice, grilled fish, and some cooked vegetables.
But to Isagi, in his hungry state, it felt like a feast.
As they ate, the silence was broken only by the sound of cutlery and the gentle wind coming through the open window.
Even so, he knew he needed to speak.
He took a deep breath and interrupted the peaceful dinner: “Dad, Mom…
I wanted to ask for something.” Both looked up, attentive.
“I’m thinking about starting to go to a gym.
I want to improve my physique more completely, beyond just training on the field.” He paused briefly before continuing.
“I also thought about practicing martial arts…” Iyo tilted her head slightly, surprised.
“Martial arts?
Aren’t you already pushing yourself too hard with school and soccer?” “That’s exactly why…” Isagi replied without hesitation.
“I haven’t been pushing myself enough to reach my dream.
If I want to get there, I can’t rely only on what I already do.
I need to improve in every aspect.
And I’ve heard that martial arts can help with body control, balance, and even protecting the ball during marking.
Besides, it would also be good to know how to defend myself, right?” Issei watched him for a few seconds, resting his elbows on the table.
“That makes sense.
So, you want to borrow money, is that it?” Isagi set his chopsticks down for a moment and looked at his plate, as if organizing his thoughts.
“Yes, at least until I can pay for it myself.
The gym membership and martial arts classes will weigh a bit…
but I promise I’ll truly dedicate myself.” Silence returned to the table for a few moments.
Iyo and Issei exchanged a glance.
When they looked back at their son, they realized he was more determined than ever.
Issei sighed, bringing a hand to his chin.
“You seem pretty serious about this.
It’s not just a whim, right?” “No.
I really want to work harder to become a professional soccer player.” Issei leaned back in his chair and gave a faint, almost tired smile.
“…All right.
Let’s see how we can help.” Iyo sighed, but didn’t show opposition.
“Just don’t overdo it to the point of getting hurt.
If you’re going to do this, do it responsibly.” Isagi nodded in gratitude.
“Thank you.
I won’t disappoint you.” .
.
.
.
.
The alarm rang at five in the morning, cutting through the silence of the room.
Isagi opened his eyes with difficulty.
His body felt heavy, as if it were still trapped in the sand from the previous day’s training.
The urge to roll over and sleep more was almost irresistible…
but he had already made his decision.
He forced himself to get up.
His feet touched the cold floor, and the chill helped drive away part of his drowsiness.
He quickly changed into a simple black T-shirt, athletic shorts, and his worn sneakers.
He ran a hand through his messy hair, trying to fix it, grabbed a towel and a water bottle, and left the house quietly without waking his parents.
The street was still dark, with the streetlights gradually turning off as the sky began to brighten.
The morning air was fresh, almost cold, in contrast to the stuffy heat of the previous night.
The gym was about a fifteen-minute walk away.
He used the walk to fully wake up, observing the closed shops, flickering streetlights, and a few early workers heading toward the station.
When he arrived, he found a simple but well-maintained facade.
A red sign glowed above the entrance: “Saitama Fit Center.” It wasn’t a large or luxurious gym, but it had all the equipment necessary to train every muscle in the body…
He pushed the glass door open and stepped inside.
The space was nearly empty.
Only an older, muscular man was organizing weights.
He had short black hair parted to the right, blue eyes, and light stubble on his chin.
He wore a dark long-sleeve shirt and light-colored pants.
The man set down the dumbbells and looked up upon hearing the door close.
“Oh!
A new face around here.
Welcome, kid…
How can I help you?” Isagi approached and spoke politely: “Good morning.
I…
came to sign up.
I want to start training.” The man broke into a wide smile.
“That’s what I like to hear!” He extended his hand.
“Fujio Uzaki.
Owner of this humble gym…” Isagi shook his hand respectfully.
“Yoichi Isagi.
It’s a pleasure…” “Yoichi-kun, huh?” Fujio repeated, as if testing the name.
“Great!
We don’t have luxury here, but we’ve got everything you need to get stronger.” As he led him to the reception, Fujio began chatting casually.
“You know, I’m not even from around here.
I came from the Kansai region.
An old friend offered me this gym, and I thought, ‘why not?’ I studied physical education to be an instructor, so it seemed like the right path.
Actually, you’re my first customer today.
I opened just yesterday…” “Really?
So I’m your first customer…
Don’t I deserve a discount for that…?” “Yes, you are!
And you can just call me Fujio, I’m not that old.
As for a discount…
how about 20%?” “That sounds great!
Thanks, Fujio-san…” While talking, they had already reached the free weights area.
Fujio leaned against one of the benches and looked at him with curiosity.
“Well, I’m curious, Yoichi-kun.
What brought you here so early?” Isagi took a deep breath before answering.
His gaze became firmer.
“Soccer.
I want to become a professional.
But I know that training only on the field isn’t enough.
I need to strengthen my body completely.” Fujio raised his eyebrows, impressed.
“I like that.
It’s not every day I see someone your age that ambitious…” He lightly patted Isagi’s shoulder.
“I’ll do my best to help you with that.
So here’s what we’ll do: today will be a light adaptation workout.
No overdoing it on the first day, or tomorrow you won’t even get out of bed.” “Got it.” Fujio led him to the treadmill and nodded.
“First, ten minutes of light running.
Just to warm up.” Isagi stepped on without complaining, turned the machine on, and started running.
“So, Yoichi-kun…
what position do you play?” Fujio asked, standing beside him due to the lack of clients.
“Forward.
I want to be a striker, actually.
But I still have a lot to improve.” “A striker, huh?” Fujio crossed his arms, smiling.
“I can’t teach you how to score goals, but I can give you legs of steel.” After the warm-up, the real training began.
Fujio guided him through various exercises, always with short, direct instructions.
“Back straight.” “Breathe, don’t hold it.” “Good!
That’s it.” Even while panting, Isagi didn’t stop early.
When his muscles burned, he just clenched his teeth and kept going.
After nearly an hour, he finished the workout.
“That’s enough for today.
If you keep going, tomorrow you won’t even get out of bed.
The body needs to adapt.” Isagi wiped the sweat with the towel he had brought, still breathing heavily, but with a faint smile.
“I understand…
but I wanted to keep going.” “Are you crazy?” Fujio laughed loudly.
“First time I’ve seen a beginner like this.
You’re really determined…
reminds me of when I started.” Isagi looked a bit surprised by the compliment.
“Thanks…
I just don’t want to waste time.” “And you won’t.” Fujio grabbed a water bottle and tossed it to him.
“I’ll take care of that.
You just need to keep showing up early.” The two sat on a bench for a few minutes, letting their bodies rest.
The initial silence was broken by Fujio himself, who clearly enjoyed talking.
“Did you know I have three kids?” he said suddenly, adjusting his long-sleeve shirt.
“The oldest is nineteen and just started college.
That’s one of the reasons I moved here—the university is better.
My middle child is seventeen, in his last year of high school.
And the youngest is fourteen and studies at a private school.
And my wife…
ah, she’s a gem.
Opening this gym was only possible because she believed in me.” Fujio’s eyes shone as he spoke about his family, and Isagi listened attentively.
“And you, Yoichi-kun?” Fujio tilted his head curiously.
“Do you have a girlfriend?” Isagi let out a small laugh, scratching the back of his still-sweaty neck.
“No…
I’m not even thinking about that right now.
I want to focus entirely on soccer.” Fujio raised his eyebrows and burst into laughter.
“Ha!
Fair enough!
But I’ll tell you, kid…
when you do have one, she’ll need to handle the routine of an athlete.
It’s not easy.” Isagi just smiled, without replying.
Fujio then stood up and extended his hand.
“So, partner…
welcome to Saitama Fit Center.
I’ll be on your case until you’re truly strong.” Isagi shook his hand firmly.
“I’m counting on you, Fujio…” _____________________ (A/N: First of all, thank you for reading this story.
Your support there also helps a lot in keeping the story updated consistently.
I hope you continue enjoying Isagi’s completely cursed new life in this crossover world.)