Under Final Disaster

(The pace is not too fast, the male protagonist is growing up, and the female protagonist is single) An ordinary college student from Blue Star accidentally traveled into the body of a young man with the same name, only to find that the world is full of crises. In order to survive, he can only continue to strengthen himself. But by chance, I discovered that I was getting closer to the truth of the world. That is the source of everything - the final disaster!