The constant care of his mother, uncle, and childhood friend Kousetsu perplexes Ittoki Sakuraba. Despite his objections, Kousetsu persistently follows him around, disregarding his plea for personal space in the name of his safety. When a kind and pure-hearted classmate, Satomi Tsubaki, asks him out, Ittoki only realizes the severity of his situation. He discovers her true intention to assassinate him during their visit to her home. Ittoki's uncle and Kousetsu unveil their true nature as ninja, coming to his rescue. As the story progresses, Ittoki learns that he is the 19th successor to the esteemed Iga ninja clan and the Koga, their archenemy, is targeting him. In order to improve his skills and safeguard himself, he must enroll in the Kokuten Ninja Academy.