Although Inuzuka Takashi (voiced by Hiroki Takahashi) was born in a martial arts family, he is absolutely against violence. One day, a cute girl with pink hair appeared in front of him and claimed to be his... fiancée? It turned out that the girl's name was Momoko Kuzuryu (voiced by Yui Kano). Because she had been rescued by Takashi before, she believed that Takashi was the world's number one master and made a wish to have the strongest child in the world with him. Momoko's enthusiasm and unrestrainedness made Takashi unable to defend himself, but during the fight, Takashi began to care about this strange girl. In addition to Momoko, the weak-looking but strong-hearted Nakajima Sanae (voiced by Aya Hirano), the short but powerful Miya Motoya (voiced by Hagoromo Miyazaki), and other girls all launched a fierce offensive against Takashi at one time. Gradually, Takashi found that he seemed to be involved in a complicated fight.