Yuka, a married woman suffering from a sexless marriage, finds herself unsatisfied and longing for intimacy. At work, she meets Toshi, a younger male colleague, who confesses his feelings for her. When he begins passionately performing cunnilingus on her—relentlessly licking and teasing her like an eager "licking dog"—her body instinctively responds to his devoted, obsessive oral stimulation. His persistent, tongue-driven pleasure begins to shake Yuka's once-principled heart, awakening a new, uncontrollable desire within her.