Rebirth of 1985's Best Doctor - Chapter 21 - I Will Take Responsibility

An ineffable rebirth, taking advantage of a mystical magic cube that was produced from rebirthing to pass through various worlds(anime, novel, movie, games, etc), collecting whatever I want to obtain!

- Description from MTLNovel

When an alien ambassador crash-lands in Tim's backyard and demands, 'Take me to your leader,' the 12-year-old does what any kid would do: he points to himself and says, 'That’s me. I’m the King of Earth.'Now, thanks to a hastily signed treaty (and a promise to hand over Jupiter), Tim’s got an armory of world-ending alien tech, an invulnerable Planetary Base in his backyard treehouse, and one tiny problem: nobody told him ruling a planet would be this hard. Between conquering Earth, fending off hostile fleets, outsmarting intergalactic bureaucrats, and explaining his absences to his Trekkie dad, Tim’s in way over his head. But if he can’t bluff his way through alien diplomacy fast, humanity might end up as collateral damage.“King of All I Survey” is a fun, heart-pounding sci-fi adventure where one kid’s lie decides the fate of Earth—and homework is nothing compared to intergalactic war.

Traveling through the world of pirates, becoming Luffy, and possessing cheats in teaching space, it is natural to make changes.

When Chambord landed on the island, the pacifist, the general Huang Yuan, appeared, and all the supernovas fell into despair except the hat group.

Seeing Zoro sweeping the world with a single sword, Sanji the Demon Kazekaku, and Luffy blasting away the oracle with his four-speed karma fist gun, the supernovas were stunned.

“Is this a supernova? I’m afraid it’s not the imperial group!”

During the war on the top, the hat regiment descended with the momentum like a royal regiment.

On Ghost Island, Kaido and Big Mom satirized: “Hey, boy, what are you going to become? Say it again in front of us!”

Luffy opened five gears furiously, his fist was as huge as a ghost island! A five-speed Yehuo fist gun! Party Kaido and Big Mom!

Luffy landed, the black stand-up collar cloak fluttered, put on the helmet, and whispered domineeringly:

“I’m Monkey d Luffy, the man who wants to surpass you and become the One Piece!”

- Description from novelbuddy

Usami is a beautiful classmate with good morals and top grades. At school, she views Sakuto as her rival. But when he bumps into her after school, he sees a different side of her. She was playing at an arcade after classes, and she had this innocent smile that one couldn’t imagine on her at school.For the sake of getting along with her, he gets close to her at school and then plays together with her after school. They each have their places where they can deepen their bonds, and at last…This is the start of a heart-warming love triangle romcom!