MTL - My Koi Sister is Three and a Half Years Old - Chapter 474 karma

An 18-year-old poor college student tried to apply for a job as a tutor but his life almost ended as demons' meal. In his last breath, a mysterious woman gave him a strange power. When he opened his eyes he had turned into a demon with a system that would turn him into… A pervert.

Now he must lived with his dual identity as a model student named Ethan and an incubus named Damian.

Reiji Saeki, who lives in the north eastern countryside town, lost his life in an accident during summer vacation. ……But before he knew it, a mysterious ball of light hovered in front of his eyes in a world of whiteness. That ball of light was a magician from a parallel world, and is looking for a person qualified to inherit the magic they had created to prevent it from being lost. Reiji, who rode on that suggestion, now lives in the parallel world Elgin, with a new body and powerful magical power.

(This is a sweet love story anthology, don’t be fooled by the first story!). Bai Qiuyi has a curse on her body: if she does not take the antidote, her whole body will be as painful as if her bones were being scraped. And her antidote was a specific type of men’s semen.

—The full text is sweet, super sweet, and the sugar content exceeds the standard.

An ordinary medical student suddenly got the blessing of the system and could directly see the patient’s health! Since then, treating illnesses and saving lives has become commonplace, and he has also become a legend in the medical field.

- Description from novelbuddy