The Extra of The Lunerra - Chapter 5: Volume I - 4: Changed Brother

Ron finds himself reborn in the world of One Piece, stranded on a remote island in the East Blue. But he's not just any ordinary child—he’s bonded to a mysterious sign-in system that grants him powers with every new location he visits.At his first sign-in, he unlocks the legendary Sun Breathing Technique, along with a boost to his vitality. From Shitmotsuki Village to Skypiea, Enies Lobby to Marineford, Ron travels the world, collecting extraordinary rewards that make him a force to be reckoned with. The Raikiri, one of the 21 Great Grade Swords, Armament Haki, Observation Haki, and more fall into his hands.As Ron steps onto the battlefield of Marineford during the legendary Summit War, the mightiest warriors—Four Emperors and Marine Admirals alike—pause, stunned by his presence. But Ron merely waves them off, “Don’t mind me. I’m just passing through.”Join Ron on his journey across the Grand Line as he signs in at iconic locations, growing stronger with every step. This is not just an adventure—it’s a legend in the making.

Jotaro awakened his Stand at 17 years old, but unexpectedly bound to a bastard system. Under the system's effect, he was forced to go to other worlds. In order to return to his own world, Jotaro had no choice but to complete the tasks issued by the system.Demon Slayer world: “Yare yare, Muzan, there's only one reason you failed, and that is, you pissed me off!”One Piece world: “You bunch of guys, I’ll be the one to judge you!” While violently beating up the Celestial Dragons, Jotaro completed a research paper on sea king-type creatures.Naruto world: “The one judging you is my Stand, Star Platinum!” Star Platinum, the true god of ninjutsu, ultimate hand sign speed. You call yourself the Copy Ninja?Originally, Jotaro only wanted to find a traditional Japanese woman to marry and have children, but he seemed to have underestimated the Joestar bloodline's attraction to women. Unknowingly, the women surrounding him grew more and more, and all willingly.The chatter of lovely women behind him made him extremely annoyed.He suddenly turned around and shouted, “Yakamashi! So annoying! You stinky hags!”[1st World: Demon Slayer2nd World: Tokyo Ghoul3rd World: One Piece4th World: Naruto]

Beneath the peaceful façade of the modern world, an undercurrent of shocking crimes roils in the underbelly of society.

The prospective college student Luo Ji, who is enjoying the last summer of the third year of high school, has undergone earth-shaking changes at this moment after accepting the invitation of the game friend and becoming the player of the game of “Civilization Rise”.
This is a war game between the world and the world, and it is a fierce collision between civilization and civilization!
To annex the five continents, sweeping across the three oceans, and see how Luo Ji led his people, in this powerful enemy look around, the battlefield of the heroes to fight for a battle to the most powerful imperial civilization!

- Description from uukanshu translation