Sisters without family ties who were adopted by a wealthy man. This man wore the mask of a good person but was actually a lecherous pervert. The man, now their adoptive father, would always pick on the older sister. In contrast, the younger sister was showered with affection. To protect her sister, the younger sister decided to become a maid and serve her. Taking advantage of the younger sister's feelings for her sister, the hulking adoptive father pounces on Yui! Yui's frail body is ravaged to the point of breaking as she is repeatedly raped, gradually losing her sanity.
