Arina is a class president. But she has a secret. She is actually a magical girl sent from a magical world. But her father, the King of the magical world, suddenly passes away. Arina decides to succeed to the throne, but her magical power isn't enough yet. When she is at a loss what to do, Aramaki, her assistant, gives her an advice. According to Aramaki, she will be able to improve her magical power by feeling sexual pleasure. She gets mad because tentacles are necessary to do that, but there is no choice. Like this, Aramaki's severe training starts now...