Rino married Junji, with whom she shared excellent physical chemistry. Junji had a son from a previous relationship, Koji, but this didn't stop the couple from enjoying a passionate sex life. However, when Rino learned that her husband was facing the threat of being laid off, she decided to sacrifice herself for his sake and offered her body to her boss, Sada. As a result, her relationship with her husband gradually cooled, eventually leading to a sexless marriage. One day, Rino discovered her own underwear, which she had thought she'd thrown away, in Koji's room. This awakened memories of her own body, making her heart race uncontrollably. Imagining her stepson's figure, she became overwhelmed by an irresistible urge to seduce him. Unable to suppress her desires any longer, she approached her stepson in a seductive, alluring manner.