Rintaro Shido, a high school student who aspires to become a full-time househusband, is in the class with a very popular idol, Rei Otosaki. The two have no connection other than being classmates, but their relationship changes drastically when Rintaro serves Rei a home-cooked meal after she nearly collapses from hunger! The food was so delicious that Rei said, "Can I come here every day to eat?"...?!

In the back of the forest lives Allen, the people-hating wizard. He is feared by the people around him and called the "Demon Lord".

One day, while living out his life as a hermit, he finds a young girl named Charlotte who collapsed. Although innocent, she was accused of evil wrongdoings, had her engagement broken and was forced to flee her country.

Upon hearing that, Alan recalled the bitter experience of being betrayed by a party he once believed to be his companions. Hearing the story of the 17 year old’s exploitation, Alan decides, “I'll let her live in my mansion, and I'll teach her all sorts of bad things…"