The Rubber Hero

— Run faster! — the red-haired devil shouted at me.

— Shut up! — I shouted back and sped up.

Right now, I was running barefoot along the beach while ropes tied around my torso helped me drag giant tires behind me.

Their weight was definitely over 60 kilograms... And to think this was only the second week of training.

Yes, such difficulties already in the second week... This is fucking insane, guys...

No wonder everyone quit, crying to their parents...

During these two weeks, sensei gave me a goal: gain weight and muscle mass, then he would teach me combat arts. But seriously, why does a 12-year-old kid need to drag a 60-kilogram load of tires!

I won't grow like this!

Having finally finished my first 3 kilometers, I sat down exhausted.

— Not bad, not bad — he grinned and walked up to me.

— Not bad? You made a 12-year-old run across the beach with a load heavier than his own weight and all you say is "not bad"? — I asked, wiping sweat as I stood up.

— Yeah, got a problem with that, brat?!

— Damn right I do, sensei!

We glared at each other and then butted heads.

— Tsk... — I clicked my tongue and continued running. — Guess I'll have to make you say "Good job" then.

He just stayed silent. Though he hid his emotions and intentions, he couldn't hide his actions.

For the first three days, he was strict with me, but after one incident, Muramatsu gradually started becoming softer.

The thing was, he asked me to swim 500 meters during our first training days.

And me? I didn't refuse... I agreed and thought I'd test if I had any weaknesses.

The first 30 seconds went fine. I was moving forward without issues, but... After those 30 seconds, everything went wrong.

I stumbled and sank into the water. My body weakened suddenly, as if something was pulling me down... I couldn't get out, and I was running out of breath...

Until Muramatsu pulled me out.

That's when I understood and noted my first weakness:

Sea water and still water.

I carefully explained to sensei about myself and my Quirk, as well as about Haki.

You might say I shouldn't have told him, but I think it was the right decision. After all, he could sense when I used Observation Haki and could hide his emotions and presence.

But most importantly... After that, Muramatsu started treating me normally.

And now, to earn his full trust, I was doing these training sessions.

The shelter became like a resting place for me.

Wake up at 6 AM, wash up, go for a run, come back, eat breakfast, then train.

After that, I return in the evening, have dinner, and crash into sleep.

Yeah, I was told many times to stay at the shelter, but I outright refused.

And today was the last day of training. My final test was to run 10 kilometers along the beach...

Even though training only started two weeks ago, I've become more enduring and tougher. My muscles are slowly showing, and the aching pain is fading.

This is the result of such a short time... I'm afraid to imagine what will happen if they train me seriously. That said, I don't want to become a musclehead like that red demon.

— Ha... Ha... — I exhaled, collapsing onto the sand.

— Already worn out? — Muramatsu asked me.

— To be honest, yes — I admitted. — But, sensei... I passed, didn't I? — I asked confidently, grinning.

— Tsk — he clicked his tongue. — After this, don't even think about leaving until I say so, brat.

Grinning, I slowly tried to stand up, but feeling dizzy, I nearly fell—if sensei hadn't caught me.

— You're a troublesome kid, Luffy.

It was the first time he said my name... It made me feel warm and happy inside.

With those thoughts, I closed my eyes and blacked out for a while.

...

Evening.

— Woke up in an unfamiliar place again — I muttered, staring at the wooden ceiling.

Slowly getting up, I looked around.

— Well? Where did I end up this time?

— This is our home — an unknown voice answered.

Turning around, I saw a girl about my age with spiky red hair tied into a sticking-out bun on the left side and big green eyes.

She was wearing a pink skirt and a yellow hoodie with black-and-white sleeves.

— Who are you? — I looked at her blankly. — Wait... Those eyes... That hair... You're sensei's daughter? — I asked.

— Yep — she smiled. — I'm Itsuki Kendo. Nice to meet you, Luffy-kun. Just Itsuki is fine — she greeted me energetically.

— Ah... Yeah — I nodded. — I'm Monkey D. Luffy. Though I guess Muramatsu and Miss Kendo already told you about me.

— Yep. Dad's been talking about you a lot lately — she kept speaking cheerfully.

— Oh? That demon talking about me? Hoo... — I smirked. — Seems like someone's starting to respect me.

— Nope. He says you're too loud, weak, pathetic, and a complete jerk.

That made me trip and faceplant on the floor.

— Demon...

— Hee-hee-hee — Itsuki laughed. — But he always says one thing: "He's got strong willpower."

Those words made me smile.

— By the way, Father called you to the dojo. Come on, I'll show you the way.

Following sensei's daughter, I chatted with her.

Turns out she really is my age.

Right now, like me, she's on summer break. She also trains with her father and dreams of becoming a hero.

Some weird superheroine...

Her Quirk is the same as Muramatsu's—Big Fist, which she demonstrated to me.

— Here we are — we arrived at the dojo. — Weird, I only meant to walk you to the exit — she said, looking around in surprise.

— Well, I had fun talking with you too, Itsuki-chan.

— Oh, come on. Just call me Itsuki — the redhead smiled and pulled out her phone. — Can I have your number?

I was about to answer, but...

— How dare you ask my daughter for her number?! — Muramatsu roared, grabbing me by the collar and yanking me inside.

Sighing, I barely managed to wave at her.

And now... I was hanging upside down, my hands behind my back, my abs burning from holding a bridge position.

— Hit on others, but not my daughter!

— Actually... She asked for my number, and besides, I left my phone at home today.

— Don't give me excuses! I won't let you have my daughter!

I twitched my eyebrows in irritation and stood up, glaring at this idiot.

— I'm not interested in your daughter.

— So you're saying she's not pretty?! — He found another reason to argue and headbutted me.

— What, you got an Electra complex or something?!

— You little—!

After arguing for several minutes, we calmed down and sat facing each other.

— Brat, I want to congratulate you... You passed my tests, and we can begin real training — he said seriously. — But I'll warn you in advance... The training, techniques, and methods I'll teach you are extremely difficult.

— So... You're saying I might end up crippled?

He slowly nodded.

— Our family has possessed the Big Fist Quirk for generations — he enlarged his fist. — But at its core lies spiritual energy.

I listened carefully, memorizing every word.

— You mentioned you don't just have a rubber body Quirk, but also something you called Haki, right?

— Yeah. Haki is energy present in all living beings. It's similar to your spiritual energy, but... My family didn't have these abilities, though my uncle... He could use them.

— And how many types of "Haki" have you learned? — he asked.

— There are three, but more or less I've learned two — I answered, surprising him. — The first lets me sense danger, auras, and emotions. The second, which I awakened during the competition, let me overwhelm others' willpower, knocking them out... As for the third... — I tried focusing on my hand, but nothing happened. — It's some kind of spiritual, invisible armor — I answered uncertainly.

He pondered deeply, then stood up.

— Stand — Muramatsu ordered.

I obeyed.

The next moment, sensei suddenly attacked me. He let me sense his intent, so I could follow the flow of his strikes.

Barely dodging three hits, he stopped and smirked.

Then suddenly, I couldn't predict where he'd strike. I felt thousands of possible attack patterns, but the outcome was the same...

Death.

His fist stopped a millimeter from my face, the wind pressure alone making me flinch.

— Listen. You're good at sensing attack flows and intent behind strikes, and your instincts are sharp... But you react too strongly to them. You can't distinguish feints from real attacks.

— I see... But how? When you attacked seriously, I saw thousands of possibilities... How do I know which is real?

The redhead smiled and walked to a punching bag.

— Every strike has its trajectory... — He threw a few light punches. — But what I did earlier were... let's say, intimidating or fake strikes — He repeated the motions, and I saw multiple fists that didn't touch the bag—only one hit.

— Good... Now you try.

— Can I even do it?

— Won't know unless you try.

Adopting the stance I'd learned from watching Muramatsu, I closed my eyes and focused.

— Relax your shoulders and breathe steadily.

A strike that would help me feel.

After two failed attempts, I sped up but still couldn't get it right.

"Focus and throw fast punches..."

Not giving up, I kept striking from all angles, even closing my eyes to better sense the flows.

I lost count of how many punches I threw.

My hands burned, my soul trembled with lightness... but something felt off.

— Luffy! — Sensei snapped me out of it.

— Huh? What? — I looked at him blankly.

— You were so focused you didn't notice? — He grinned, eyeing my hands.

My fists were coated in a black, metallic sheen, smoking slightly. The moment I realized, the coating faded, and pain shot through me.

— Kh... — I clutched my wrist.

— Well... — The red demon sat down, pulling bandages from his pocket to wrap my bleeding knuckles. — We didn't achieve what we wanted, but we got something else. Now we know what that "invisible armor" is.

— Armament Haki... That's what I'll call it — I grinned.

— Wouldn't say it's a bad name, but not great either.

— Shut up...

— Hah... Stay with us tonight — he suddenly offered. — Tomorrow, your real training begins.

— Not afraid I'll seduce your daughter— Ow-ow-ow! What the hell are you doing?!

— Your fault — he smirked, a vein bulging on his forehead.

And so... I stayed at the Kendo household. After dinner, I went to sleep... in the dojo.

I borrowed Itsuki's phone to call Hayami-san, letting her know I wouldn't be back.

She said she'd inform the director and wished me goodnight.

— Thanks... — I returned the phone to Itsuki and looked around. — Just so you know, I called my own number — I whispered.

She blinked, then nodded happily.

After wishing everyone goodnight, I lay down on the futon spread out in the dojo.

Staring at my bandaged hands, I smiled.

Soon, I'll master this power—and no one will stop me from living how I want!