A dramatic story-driven production! Yui's life changes when her biological mother remarries, forcing her to live in a new household. As she begins living with her stepfather, her relationship with her stepbrother gradually deepens. He's incredibly attractive and well-built, and her feelings for him grow stronger each day. Drawn to him, she finds herself masturbating frequently. One day, her stepbrother forcefully takes her, and conflicting emotions of resistance and arousal are vividly portrayed. Later, Yui witnesses her mother and stepbrother having sex—an intense, shocking turn of events in this erotic, dramatic tale.