An accidental transmigrator: a fat, socially withdrawn shut-in from the 21st century, plus a System.
Some System: Welcome to the Land of Illusory Dreams. Your cultivation journey begins now. Are you ready, player?
Shut-in: Cultivation? Isn't that just staying up all night? Easy.
Some System: Esteemed player, we will now choose your cultivation target. Please get ready.
Shut-in: What the hell, did I transmigrate?
Some System: Esteemed player, the current System version is outdated. Please select smart services. [Beep: logging out automatically]
The shut-in, sweating profusely, has no choice but to open smart services.
P.S.:
1. One-on-one romance (bottom is the protagonist)
2. This is a transmigration story, possibly transmigration into a book, with a built-in System
3. The story progresses according to the characters' personalities.
Theme: To be added