Arisa Miwa, a poor college student, is transferred to the body of Aisha, the daughter of a super rich duke in the game world. A cat named Heal System appears before her and orders her to cause trouble for various people, including the heroine Lucy, as a villain.
Arisa follows instructions, but things don't always go as planned. One moment she seems to be harassing Lucy, the next she saves her life; another moment she seems to be harassing the maid, but ends up rescuing her from a difficult situation; and another moment she seems to be bullying an orphan, but ends up giving him the opportunity to become independent.
Prince Claris, who had been watching Arisa's behavior, invites her to a ball.
The two end up becoming engaged, and Lucy, who was originally meant to be married to Clarice, ends up becoming a knight. Will the game be able to reach its happy ending?