After losing her mother, the Kasagi household became a single-parent family with just father and daughter living together. The father worked hard, dedicating his life to providing for his daughter, and Ichika grew up inspired by his devotion. However, Ichika began to interpret his sacrifices as acts of love meant solely for her, and feelings deeper than a daughter's usual affection started growing inside her heart. Unable to suppress these emotions, she resorted to daily masturbation to ease her inner turmoil. Then one day, when her father mentioned the possibility of remarriage, Ichika—usually well-behaved and never demanding—felt her long-restrained desires finally explode beyond control!!