Jujutsu Kaisen + near-invincible protagonist + faithful to the original + in character
A Jujutsu Kaisen fanfiction
I'm in Japan, just got off the plane. I'm an international student by profession, and my hobby is betting on boat races. I've lost 400,000.
I only meant to spend a few years as an exchange student before heading home, but there was no escaping the mess with Satoru Gojo and Suguru Geto, and I was dragged into it.
Since I was there, I rescued Riko Amanai and then sent her back to China. And so the story of Jujutsu Kaisen begins. (Note: The protagonist hasn't transmigrated. He's a disciple of China's Jujutsu Academy, the Qingxu Academy.)
(Note: Although this story makes some changes to the original and adds new elements to the setting, the overall pacing and key plot points will stay fairly close to the source.)