Five hundred years ago, Great Demon Hunter Mi Wan was reborn into the modern era. With the strength to crush all demon clans, she opened an expensive pet shop. A single diagnosis costs three hundred thousand dollars, and for a million dollars, she can expel and treat demon poison. However, due to her unstable spiritual power after rebirth, Mi Wan will go into a coma whenever her spiritual power is depleted, and her soul will fly to the male protagonist's side. The male protagonist is the current demon king who possesses the highest demon level, has a hobby of buying land and building parks, is devoted to the peaceful coexistence between humans and demons, and protecting the environment.