As summer arrives, Maria selects a new swimsuit and cheerfully puts on a fashion show in front of the mirror, feeling proud of her stunning, model-like appearance. Suddenly, her stepson Haruto walks in and is instantly captivated by her bikini-clad figure—her voluptuous body and the suggestive lines of her swimwear leaving him spellbound. Sensing his gaze, Maria feels a mischievous urge and demands an oil massage. As Haruto touches his stepmother's lush body for the first time, he's overwhelmed by its sensual allure, slowly giving in to desires beyond mere massage. Maria's breathing grows heavy, and their relationship begins to cross the boundaries of family, descending into forbidden passion.