Takamaru Ikusabe, a boy attending Jippou Academy, was living a peaceful life in pursuit of love, despite constant cockblocking by his landlord's daughter, Narika Shihoudou.

One day, Takamaru encountered a girl who captured his heart at first sight. Her name was Haruka Takamori.

That night, Takamaru and Narika were attacked by a mysterious group of ninjas. The one who saved them from the crisis was none other than Haruka, wearing kunoichi gear.

Haruka called Takamaru her master and asked him to perform sexual acts with her. It turned out that Takamaru was the young master of a heroic ninja clan known as the Crescent Moons, and via sex, he had the ability to provide a supernatural energy called Sex Power (SP).

Haruka obtained some SP from Takamaru and managed to fight off the ninjas, but that was only the beginning of a long and arduous battle.