My older brother has a lewd and perverted personality, constantly craving to do erotic things with his younger sister. What started as playful teasing gradually spirals out of control—he begins touching her breasts and even progresses to kissing her. Obedient and highly sensitive, the younger sister always submits to her brother's desires, willingly accepting anything he does. As a virgin, she is slowly molded according to her brother's preferences, being taught increasingly erotic acts until she ultimately becomes the perfect love doll tailored exactly to her brother's liking.