Ichika is a serious and reserved girl going through puberty, her body gradually developing with increasingly prominent breasts. With her striking large eyes, she discovers masturbation through knowledge gained from erotic manga. Beyond that, she harbors secret feelings for her older brother, slowly gathering the courage to act on her emotions. The story intimately portrays her pure, blossoming affection intertwined with the bittersweet pangs of young love and the physical changes of adolescence. A delicate narrative exploring a teenage girl's inner world, touching on themes of beautiful girl, incest, and masturbation.