Arisa (Kanna Misaki) grew up in a single-parent household and lives with her mother Michiko (Ayako Kano). - My mother supports the family by working as a cashier at a supermarket during the day and selling snacks at night. - One day, her mother came home drunk from work accompanied by a man. - The first time I see my mother as a woman. - And then there's the presence of a man she's meeting for the first time... - Soon after, my mother remarried the man from that day, Osamu Sakai. - The three of us started an awkward life together. - For the adolescent Arisa, the casual behavior of her stepfather makes her tingle deep within her body, which is just beginning to awaken. - Even though I should hate my stepfather in my heart, for some reason my body craves the scent of a man... - Eventually, Arisa smelled her father-in-law's underwear and pillow and learned to masturbate. - And her father-in-law also noticed Arisa's actions...