Konatsu is a younger sister who has loved her brother too much since she was little. One day while their parents are traveling, the older brother witnesses Konatsu masturbating while saying "Big brother..." and finds out that he is peeping on her. Konatsu lets her touch her big breasts and seduces her, saying, ``You can do whatever you want, okay?'' The older brother can't resist the temptation of his cute younger sister...
