After the protagonist completely breaks down emotionally and takes his own life, he discovers that he has transmigrated into a book.
He has become a vicious cannon-fodder character who looks and is named exactly like him, and whom everyone despises. Everyone's attention belongs to the protagonist, a male lead who is the same age as him.
If the protagonist is a radiant deity, then he is a rat in the gutter.
If you don't court death, you won't die. In the book, the vicious cannon fodder does every bad thing imaginable and ultimately gets the punishment he deserves, dying a gruesome death.
The protagonist: No problem. I didn't want to live anyway.
Bound by the text, he can't take his own life before the story allows it, so he has no choice but to follow the plot and do all the wicked things he doesn't want to do, constantly making trouble for the protagonist and fulfilling his role as the book's vicious cannon fodder.
At last, the cannon fodder's fate reaches its end. Standing on the rooftop, the protagonist gazes down at the lights twinkling below. A look of relief and calm flickers across his face, then vanishes.
The next second, a man rushes up behind him and pulls him into his arms with all his strength.
Then the protagonist's scorching lips land on his cheek, his neck...
The righteous yet secretly unhinged protagonist (gong) x the self-destructive, vicious cannon fodder who is actually a little angel (shou)
Theme: Redemption is a wondrous thing.