Zhi Nan Er Shang

Troy Qi was a young MMA world champion, crowned the strongest man in the world after a career-defining match. But his reign abruptly ends after he saves the life of troubled high school student Tori He, as she accidentally falls from a rooftop balcony. When Troy awakens, he finds that he died... and his soul has transferred into Tori’s body! Now the world’s strongest fighter must face his greatest battle yet: being a female fighter in high school.
(Source: Tapas)