Keitaro Urashima promised a girl 15 years ago that they'd get into Tokyo University together. Now a second-year ronin (failed applicant), he heads to his grandmother's inn to focus on studying. But to his shock, the inn has become an all-girls dormitory—Hinata House!

When resident swordswoman Motoko returns from a training camp to find a man in the dorm, she declares war on Keitaro. But despite her fierce protests, her heart starts pounding every time she sees him. Is this… love?