Okay so it turns out that when they were young like middle or high school they knew each other and the top confessed his feelings to the bottom. So the bottom took advantage of his feelings and graped him, then had a group of other guys gang grape him while having him locked up in a room or something. The bottom then got into some kind of accident and that's why he doesn't remember anything that the top is talking about. So the top is getting his revenge by literally doing what was done to him when he was a kid (they were still teenagers and not adults at the time)

SOMEONE PLEASE SAVE THIS GUY FROM THE AUTHOR'S IMAGINATION!!! PLEASE WURHGHHHH *throws up and presses next chapter* JUST KILL THE ML(????) PLEASE SOMEONE CALL THE POLICE INTO THIS MANHWA. FIGHT OR DIE TRYING MC PLEASE