Raised in the mountains and trained with a sword since childhood, Yoichi Karasuma has mastered the Ukiha Divine Wind Style by seventeen, so his father sends him to the city to learn how to live among people. He boards at the Ikaruga dojo with the four Ikaruga sisters, where the eldest, Ibuki, serves as assistant instructor and keeps the household in order. Clumsy with modern life and hopeless around women, Yoichi stumbles through school while rival swordsmen start turning up at the dojo's door.