Aaron, a magician who lives deep in the forest and hates to interact with people, is not only called the "Demon King", but also feared by people around him. He lived a hermit life, and one day he found a rich girl, Charlotte, lying on the side of the road. She was accused of a crime she did not commit, and her engagement was broken off, so she fled from her homeland to come here. After hearing all this, Aaron recalled the bitter experience of being betrayed by a member who he believed to be his partner. Hearing that she was only seventeen years old and had been living a life of oppression, Aaron made up his mind - to let her live in his house... and instill all kinds of bad but happy things in her.