Y/n Dracizia is a human-world princess and heir to the throne of her kingdom. She is invited by Lord Diavolo, son of the Demon King and heir to the Devildom, to participate in a interdimensional exchange program for the purpose of an alliance. Through her experiences, she shares and learns magic from all the three realms. Though one particular demon isn't too keen on her ambitions and desires, and strives to keep her under control by any means necessary.