The Tachibana household consists of a married couple, Reika and Ataru, and their ordinary life as a family of three. They live in a renovated traditional Japanese house transformed into a stylish, modern urban space. One day, while cleaning her son's room, Reika discovers a book belonging to Ataru, who is going through puberty. Surprised by how much more erotic its contents are than she expected, she finds herself unable to look away. As she continues reading, she becomes increasingly absorbed in the material, eventually becoming so aroused that she begins touching her own pussy. A strange, everyday narrative unfolds, contrasting the warmth of family life with the hidden desires lurking beneath the surface.