One night in a merchant's mansion, a kunoichi (female ninja) named Yasuzuis violated by a group of men under the effect of "Aura of Ogre", called "Demi-Ogre".Although she had kept her virginity, the Demi-Ogres keeps sexually tormenting Yasuzu.Now the only thing Yasuzu can think about is her senior kunoichi Botan who she has longed for.