Five years after divorcing her husband, Maika Asai takes her son Masaru and his friend Kenta on a clam-digging trip. On the beach, they happily gather clams together, sharing a warm family moment. However, back at the inn, Maika catches the familiar masculine scent in Masaru's discarded underwear and is overwhelmed by desire, leading her to masturbate. At that moment, Kenta sneaks into the room and catches her in the act. Mixing shock with curiosity, he begins blackmailing her, taunting her as "Auntie." Soon, he starts to dominate and humiliate her like a bitch in heat. Though initially hesitant, Maika gradually becomes aroused by his actions. Ultimately, even her beloved son Masaru falls under Kenta's influence. A complex story unfolds, entangling emotional conflict with uncontrollable physical desire.