Naruto System in One Piece - Chapter 465: Three Legendary Sannin Showdown

Have you ever thought that the state of the world as it presently is, could revert to the laws of the ancients? When a series of strange incidents beginning with the disappearance of his friend led Luo Yuan to question the possibility of an apocalypse, he becomes embroiled in the midst of a global-scale chaos.

Evolution has turned the flora and fauna of the vast and bountiful Earth into something that had never been seen before. Coincidentally, the all-dominating Homo sapiens have ended up at the bottom of the food chain. From mystery to crisis, will Luo Yuan discover a means of saving humanity by racing to the top of the food chain? Or will he strive in accordance with the law of the jungle? It is the dawn of an age of the survival of the fittest.

- Description from Novelupdates

In the beginning, when they all thought that she was “he”….

ML #1: We will be brothers for life!

ML #2: This time I’ll reluctantly let you have the #1 seat.

ML #3: I will properly repay royal teacher!

ML #4: Ah Rong is my closest little brother, I trust him.

Afterwards…

MLs: I’m seriously such a fool.

MLs: What do I do, I think I’m gay. I fell in love with my bro/rival/teacher….

Afterwards….

MLs: I’m straight! As straight as steel!

Note:
MC is a girl crossdressing as a boy, she knows how to fight, and naturally possess the gold finger halo from the author.

All the ML(s) is the same person, 1v1, sc, HE

- Description from Novelupdates

Kakashi has lived a sheltered life within the protective confines of a barrier, which shielded them from the dangers that lurk outside. Raised by his devoted mother, Ako, and loving sister, Tokah, he only know a world of happiness and joy. Living in a world where he thought nothing could go wrong.But when a group of men invades their home, everything changes. In the brutal assault, Kakashi witnesses his mother's tragic death, a moment that shatters his naive understanding of safety. While his sister manages to escape, Kakashi is captured and subjected to experiments designed to exploit his hidden powers.Years later, amidst the ruins of a collapsing facility, granting Kakashi a chance at freedom. Rescued by an academy dedicated to training gifted individuals, he discovers not only the extent of his abilities but also the resolve to seek vengeance against those who tore his family apart.Driven by the desire to reunite with Tokah and avenge his mother's murder, Kakashi embarks on a journey filled with action and self-discovery.As he navigates the treacherous underbelly of a world rife with superhuman conflicts, he must confront his own problems while mastering the very powers that once made him a target.

Born into a unique world where villages fight to gain power and control, the main character, Shi Hao, is a genius blessed by the heavens born under the poorest of conditions. His clan, however, has a mysterious past. To rise up and become the genius he is meant to be, the clan goes through every effort to aid his cultivation as they battle through fanatical monsters and engage in power struggles with other clans. His journey will bring him through unknown lands until he is able to become a person that can truly shake the world.