Chapter 4: Babysitting a Future Pirate King

(Authors note! This will only slightly focus on his brotherly relationship with luffy)

The open sea stretched endlessly before us, waves gently rocking the ship. The air was crisp, the sky clear, and for the first time since arriving in this world, I allowed myself to relax.

Or at least, I tried to.

"ACE! I'M HUNGRY!"

I sighed, rubbing my temples. "Luffy, we just ate twenty minutes ago."

"But I'm still hungry!"

I stared at him. He stared back, eyes wide, mouth slightly open, like a puppy begging for scraps.

"…Fine."

His face lit up. "Yoshhh! You're the best, Ace!"

"Yeah, yeah," I muttered, already moving toward the ship's small supply stash. I wasn't even surprised at this point. This was Luffy. If there was food anywhere on this ship, it was going into his mouth.

Koby, who had been nervously practicing his salute, watched the scene unfold with wide eyes. "I-Is this normal for him?"

I snorted. "Get used to it."

I tossed Luffy a small sack of food, and he immediately ripped it open, devouring everything inside without a second thought. I leaned back against the railing, watching him like a parent watching their hyperactive child.

He was so much like the Luffy I knew from the series, but experiencing him firsthand? It was on a whole different level.

And, somehow, I'd become his babysitter.

---

Chaos in the Kitchen

It turned out our food supply was not built for Luffy's stomach.

"Crap," I muttered, staring at the near-empty stash. "We're gonna need more food soon."

Luffy, completely unfazed, licked his fingers. "Let's catch some fish!"

Koby perked up. "That's a good idea! We can—"

"I'LL PUNCH THEM OUT OF THE OCEAN!"

I turned just in time to see Luffy throw himself overboard.

"Luffy, you idiot—!"

Splash!

For a moment, there was silence. Then—

"GAAAH! A SEA KING!"

Of course.

I rushed to the railing just as a massive shadow moved beneath the waves. Luffy flailed, kicking furiously to get away from the enormous sea creature that had apparently decided he was today's snack.

I sighed. "You moron."

"HELP MEEE!"

I didn't hesitate. Grabbing a rope, I leaped over the side, swinging down toward him. The Sea King lunged—its massive jaws seconds away from chomping Luffy in half.

Something in me snapped.

I felt it before I even understood what was happening. That same strange energy from before—the feeling of something vast pressing against the edges of my senses.

And then—

The Sea King stopped.

It froze mid-lunge, eyes going wide, its body trembling.

Then, in a single panicked motion, it fled.

Luffy and I bobbed in the water, watching as the creature disappeared into the depths.

"…Whoa," Luffy muttered. "That was cool."

I swallowed hard. I had used Haki again. But unlike before, this wasn't just Observation Haki.

This was Conqueror's Haki.

And Luffy… he had felt it, even if he didn't realize what it was.

I forced a grin, ruffling his soaked hair. "Yeah, yeah, now let's get back on the ship before another one shows up."

Luffy just laughed. "You're so strong, Ace!"

I hoisted him onto the deck, sighing as he shook himself off like a wet dog. Koby stared at us, pale. "W-What was that? Why did the Sea King just—"

"Luck," I said quickly, not ready to explain. "Pure luck."

Luffy beamed. "Then we're really lucky!"

I groaned. Babysitting this kid was gonna be exhausting.

---

Big Brother Duties

By the time night fell, I had fully accepted my new role as Luffy's older brother.

It started small—making sure he actually ate food and drank water instead of just stuffing himself with meat, keeping him from falling off the ship again, stopping him from tying Koby to the mast (why?).

But as the hours passed, I found myself doing things without thinking.

Fixing his straw hat when it slid too far down his face. Making sure he didn't wander too close to the edge while he slept (seriously, why did he sleep like that?).

Even draping a blanket over him when the wind picked up.

Luffy, half-asleep, blinked up at me. "Mmm… Ace?"

"Yeah?"

He yawned, rubbing his eyes. "You're nice."

I blinked.

He grinned sleepily. "I like you."

Something warm bloomed in my chest.

I scoffed, ruffling his hair. "Yeah, yeah. Go to sleep, dummy."

Luffy hummed happily, already dozing off.

Koby, watching from the side, smiled nervously. "You're, uh… really good with him."

I sighed. "Someone has to be."

But deep down, I didn't mind.

Because, in a weird way, taking care of Luffy felt… right.

Like this was exactly where I was supposed to be.

And for now? That was enough.

The sun shone brightly overhead as our tiny ship cut through the waves. The salty breeze filled the sails, and for a moment, I allowed myself to enjoy the peacefulness of the sea.

Then, Luffy—because of course it was Luffy—stretched his arms out, grabbed the mast, and slingshotted himself into the air.

"WHEEEEEEEE—!"

I sighed. "Luffy, for the love of—"

THUD!

He landed face-first back onto the deck.

Koby rushed over, panicked. "C-Captain Luffy! Are you okay?!"

Luffy sat up, laughing like an idiot. "That was fun!"

I rubbed my temples. "You're worse than a kid."

Luffy grinned at me. "Oi, Ace! I decided something!"

I glanced at him warily. "That's never a good sign."

"You should join my crew!"

I blinked. "Huh?"

"You should be my nakama!"

There was no hesitation, no buildup—just a statement, like it was the most obvious thing in the world.

I blinked again, trying to process it. "You don't waste time, huh?"

Koby, who had been nervously watching, muttered, "T-That was fast."

Luffy tilted his head. "You're strong, you're fun, and you feel like family. So you should be my nakama!"

I stared at him. He said it so simply, like there was no reason to not join him.

And the crazy thing?

I wanted to say yes.

This was Luffy. This was One Piece. This was an adventure I had dreamed about since I was a kid.

I smirked. "Yeah. I'm in."

Luffy's grin widened. "YOSHAAAAA!"

I chuckled. "You better not regret it, Captain."

Luffy just laughed, already looking ahead.

And just like that, I became a Straw Hat.

---

Arriving at Shells Town

The first sign of land came early the next morning. The faint outline of buildings, the rising Marine base in the distance—it was exactly like I remembered from the manga.

Shells Town.

Where we'd meet Roronoa Zoro.

I was still processing that when Luffy leaned over the ship's edge, squinting at the town. "Zoro's here, right?"

Koby, who had been staring anxiously at the Marine base, swallowed hard. "Y-Yeah, but… he's tied up at the base. He's been imprisoned."

Luffy grinned. "Then we'll go get him!"

I crossed my arms. "You do realize that means we'll be fighting Marines, right?"

Luffy just laughed. "So?"

I sighed. "Of course you don't care."

Koby wrung his hands. "B-But the Marines are dangerous! And Zoro—he's a demon! He's a bounty hunter who's taken down so many criminals—"

Luffy ignored him. "Let's go find him!"

I rolled my shoulders. "Guess we better see if he's actually worth all this trouble."

"Well i definitely know he's worth more than any trouble"

Ace said in his thoughts

Koby looked between us, eyes wide. "Y-You're seriously going to break into a Marine base?!"

Luffy grinned. "Yup!"

I chuckled, clapping Koby on the shoulder. "You're gonna wanna stand back for this one."

As we docked, Luffy hopped onto the pier with his usual enthusiasm. I followed, already feeling that buzz of excitement in my chest.

This was it.

We were about to recruit Roronoa Zoro.

And somehow, I just knew—

This was only the beginning.