The Scumbag from the Future

Just like the title of the book, it tells how he, who comes from the future era, gradually becomes a scumbag in modern society. Time travel, return to campus, mysteries emerge, and reality changes. The paleness of the truth and the helplessness of the future, everything is just a game in time and space, no one can change it. This is a somewhat brain-burning reality, from the third person perspective of the male protagonist.