I'm in Naruto, but the system says I'm in One Piece.

7:30 in the morning.

After getting up and packing his things, Minato Namikaze put on his sportswear, picked up his shoulder bag, and prepared to go to Hoshino Yu's house to wake him up.

The two agreed to have breakfast early today, since they've started school and can't sleep in as late as they used to.

When they arrived at Hoshino Yu's house, Minato knocked on the door.

"Knock knock knock—"

"Yu, it's time to get up, or you'll be late."

After waiting for a while, Minato looked at the gate, which remained motionless, and felt a little puzzled.

At this time of day, Hoshino Yu's voice should usually be heard from inside the house.

"Still not awake?" Minato thought for a moment, then knocked on the door again. "Yu?"

A moment later, Hoshino Yu's languid yet slightly pained voice came from inside the house:

"Minato, just come in..."

Upon hearing this, Minato Namikaze frowned slightly and quickly took out the key from his backpack.

As best friends, they each have a spare key to the other's house, which was something they agreed upon.

If you knock on the door and there's no response someday, you can just open the door and go in.

When the door opened, Minato Namikaze was dumbfounded.

What greeted my eyes was not the usual tidy house, but a complete mess.

The vases and other items on the table were all broken, the wooden table was chipped and missing corners, and there was even a burnt smell.

"This..." Minato's heart tightened. Hearing Hoshino Yu's voice coming from the bedroom upstairs, he quickly ran up to check.

The bedroom was even messier.

Meanwhile, Hoshino Yu was lying on the bed, grinning and grimacing, fidgeting with his limbs in a strange way, and his hair was a little curly.

"Yuu!"

"Ouch~ Don't move!" Hoshino Yu winced in pain. "I pulled a muscle. I overdid it last night."

Minato quickly stepped forward, but seeing that he was being stopped, he said with a worried expression:

"What happened last night?"

Hoshino Yu's eyes darted around, remembering the excuse she had prepared beforehand, and she gave a wry smile:

"It's from my late father. He left three ninjutsu scrolls, saying they could only be opened after I started school."

"Last night I was curious and tried out a lightning ninjutsu, but I didn't control it well and this is what happened."

As he spoke, he pointed to the three slightly dusty scrolls that had been deliberately placed on the bedside table.

It's understandable that the scroll is the only memento of the parents, who were ordinary Chunin before their deaths and sacrificed themselves during a mission.

Minato leaned closer to take a look, then breathed a sigh of relief, before frowning and saying:

"You're being too impatient. You can't practice ninjutsu at home!"

As he spoke, he skillfully rummaged through the cabinet next to him and pulled out some liniment for bruises and sprains, tossed it to Hoshino Yu, and then tidied up the mess in the room.

After he finished cleaning up, he went home and brought back bread and milk.

"Eat something first, I'll go buy breakfast. Oh, by the way, should I call in sick for you?"

"Okay," Hoshino Yu forced herself to sit up. "I'll rest for two days. I won't be able to move right now."

Seeing that Hoshino Yu was alright, Minato Namikaze placed his right hand on his forehead, shook his head, and said:

"I really can't help you."

After finishing all this and bringing the breakfast back, he gave a few more instructions before going to school alone.

Seeing that the person had left, Hoshino Yu lay on the bed, looking at the newly renovated room and the fresh breakfast and medicine on the table, and couldn't help but smile:

"Minato, that guy, truly lives up to his nickname 'Little Sun'."

"Hiss~ But I still need to get used to this speed."

He rubbed the bruised and swollen spots on his body.

It's true that I have a muscle strain and body aches, but it's not to the point where I can't move.

The main problem is that I've just gained power and can't fully control it yet; I need to rest for a day or two to get used to it.

Otherwise, it's hard to say what problems might arise.

After exhaling a breath of stale air, Hoshino Yu's consciousness sank down, and he looked at the personal information panel in his mind.

[Name: Hoshino Yuu]

Age: 6

Chakra level: 0.9 (low amount)

【五维：力1/速1.2/体1.3/精6.1/印0.7】

Chakra Properties: Lightning, Water, Fire, Yin, Yang

[Ninja/Body/Illusion: None]

Item: None

[Assignable attribute points: 0]

(Reference note: The average stats of a typical 20-year-old adult are 1 in all aspects except for hand seals and chakra.)

"After just one night, all their health indicators have reached or even exceeded those of an adult..."

Hoshino Yu was secretly surprised by the irrationality of the Devil Fruit, while raising his hand and clenching his fist, feeling his own power improve.

Having already been an adult before transmigrating, it's easy to control now that my strength attributes have returned to their original state.

The main focus now is on speed.

After getting up, he limped to the table, ate breakfast, and then lay back down on the bed, soon falling asleep.

......

A secluded place somewhere in Konoha Village.

"Lord Danzo, last night, there was some noise at Hoshino Yu's house. It sounded like there was a fight going on inside, and there were subtle fluctuations in chakra."

"Everything is normal at Minato Namikaze's house."

A ninja wearing a simple textured mask knelt on one knee and addressed Danzo Shimura, who was reviewing intelligence at the head of the office.

Danzo did not respond, but simply continued reading the scroll.

After a moment, he spoke in a low, calm voice:

"Were there any unexpected incidents?"

"Reporting to you, sir, Namikaze Minato opened the door early this morning. Apart from being a bit messy inside, there were no other issues."

"Okay, I understand. Continue monitoring."

"Yes."

After the ninja left, Danzo glanced at the tightly closed door, then opened the cabinet under the table and took out a brand new book.

Looking at the book cover with the three big characters "One Piece" printed on it, and the author's name listed as Hoshino Yu, Danzo smiled with a hint of disdain.

"Hiruzen, the ninja world has been too peaceful for too long. You, the Hokage, have become quite decadent. You even read children's books like this."

After making a few sarcastic remarks, he slowly turned to the first page...

......

Two days later, in the early hours of the morning.

Hoshino Yu lay down for two whole days.

Fortunately, I've mastered the power of the Rumble-Rumble Fruit. Now that I can't sleep, I can finally think about how to develop the fruit in the future.

Elementalization is definitely the most important thing.

That speed, which is almost the speed of light, can basically evade all attacks.

As for illusion magic and sealing magic, it depends on the situation.

We should also study these two methods in the future, because having multiple approaches gives us more confidence.

Other than that, we don't need to think about powerful moves like Lightning Release for now. We can develop smaller skills, but it would be best to have Lightning Release ninjutsu as cover.

Just as I was pondering how to proceed, a faint, strange noise came from outside.

"What's that noise..." Hoshino Yu keenly noticed this, got out of bed, and grabbed the family heirloom kunai from the cabinet.

After being empowered by the Rumble-Rumble Fruit, his physical attributes have been enhanced.

He didn't think he was hallucinating.

Moreover, there were already prying eyes outside earlier, so this time it's even more direct.

After leaving the bedroom, Hoshino Yu heard a strange noise coming from the window. She hid behind the door, her eyes narrowed, staring intently in that direction.

"Is it the 'root' organization? Or...?"

"It must be Danzo."

He immediately dismissed any doubts.

The only place where Danzo's "roots" could sneak around the village late at night was Danzo's.

With the skills of Root ninjas, entering a civilian's home silently in the middle of the night is quite easy.

Seeing that the window was about to be opened, Hoshino Yu became extremely vigilant, and at the same time, several arcs of electricity flashed on the kunai in his hand.

Now that we've got the fruits, it's time to show off our talents a little.

Kakashi graduated at five, became a Chunin at six, and a Jonin at twelve.

So, at the age of six, if I discovered a Root ninja and threw a kunai at him, is that alright?

When the window was opened silently, a figure slipped in from outside and then closed the window again.

The ninja wearing the simple textured mask sensed something was wrong as soon as he landed.

After quickly scanning the area, the masked ninja decisively chose to retreat. At the same time, a kunai crackling with lightning shot towards him from the shadows!

"!"

The masked ninja reacted instantly, drawing a short blade from his back and precisely slicing open the kunai.

clang--

A metallic clang rang out as the kunai was pinned to the wall, the lightning at its tip instantly dissipating.

Without hesitation, the masked ninja vanished into the night.

The curtains swayed in the wind, and soon the room returned to silence.

Hoshino Yu stepped out from behind the door, looking at the kunai on the wall with a cold gaze.

"That shouldn't be the case. Danzo wouldn't be so impatient, and I haven't shown any particular talent before..."

He lightly leaped and pulled the kunai off, then pondered to himself.

The Root ninja masks are different from those of the Anbu, so he could naturally recognize them at a glance.

When I threw the kunai just now, I threw it with all my might. With the added power of electricity, it should have had the power of a genin's throw, but it was directly deflected by that Root ninja.

Yes, the gap between us and Jonin is still quite large.

As for the ability to instantly kill the opponent with speed after elemental transformation, let's leave that aside for now.

......

"Lord Danzo! The mission failed, and the manuscript was not retrieved. It was my negligence! Please punish me, sir!"

"You mean, you broke into a six-year-old child's house in the middle of the night and got caught?"

Upon hearing this, Danzo, who was sitting in the main seat, sharpened his gaze and spoke with some displeasure.

Hearing Danzo's deep voice, the masked ninja kneeling on one knee swallowed hard, his Adam's apple bobbing slightly, and he quickly explained:

"Lord Danzo, as soon as I entered the room, a kunai was thrown at me. It was incredibly fast and stronger than that of an ordinary genin."

"Furthermore, the kunai is also equipped with lightning release ninjutsu..."

"Lightning Release? Genin level?" Danzo raised his hand to stroke his chin, then looked at the books on the table. "Hoshino Yu, six years old... really good forging material."

......

Before dawn, Hoshino Yu got up, washed up, and changed into a brand-new set of clothes that Minato had bought a couple of days ago.

Minato probably hadn't gotten up yet, so he went straight out to buy breakfast.

For two days in a row, Minato cooked and washed the dishes for him, so he had to treat his good friend to a meal.

After the incident in the early hours of the morning, there have been no further developments.

Things should calm down in the next few days.

However, Hoshino Yu thought about it all night but still couldn't figure out why she would approach him now.

It couldn't be because of the Will of Fire's remarks; he was more convinced that it was the One Piece novels that attracted the other party.

When they got out onto the street, Hoshino Yu was looking to see what was available to eat at this hour, but to her surprise, only the bakery was open.

Just as I was about to enter, I heard an excited and urgent voice behind me.

"oi! Yu-kun!"

Hearing that familiar voice, Hoshino Yu turned his head to look.

Then, Luffy, dressed as a water column, came running towards him, waving and holding a knife.

This scene...

If I didn't know the other person's character and wasn't Huang Yaoshi myself, I probably would have run away by now.

"Mizuki-senpai, are you here to buy breakfast so early too?" Hoshino Yu asked politely as Mizuki came in front of him.

Shuizhu was panting, but not as excited as she had been a few days ago.

He brandished the knife in his hand and said with a smile:

"No, I just went into the woods to cut some wood, and I'm heading to the pond now."

"Why are you cutting down trees?"

"Building a ship, of course!" Water Column said smugly, hands on his hips, rubbing his nose, and laughing. "Building my own Going Merry!"

Before Hoshino Yu could react, the water column grabbed his hand and led him towards the pond, saying at the same time:

"Come on, Yu-kun, you're the author, look at how well I've built the Going Merry!"

Hoshino Yu was carried along by the water column and soon arrived at a pond at the edge of the forest.

"This is my Going Merry!"

"It's just that we're in the initial stage right now..." Shui Zhu scratched his head, somewhat embarrassed.

[You have received the main quest: Help the future Pirate King, Monkey D. Luffy, obtain his first real ship and aid him in sailing the seas.]

[Task Reward: 0.2 Free Attribute Points.]

Current progress: 50%

Here it comes, here it comes, a quick glance at the familiar faces and half the battle is won.

"Luffy's first ship does seem to be a small wooden boat, but the mission description suggests it's the Going Merry, right?"

"But this ship..."

Seeing the changes in the mission's progress, Hoshino Yu crossed her arms and glanced at the half-full wooden boat by the pond, sighing at the water column:

"And you, my friend, you are the real Luffy."