Arika lives a quiet married life with her husband and his adult younger brother Masato, who moved to Tokyo to pursue stage acting. Because her husband often comes home late, she and Masato frequently eat dinner alone. One night, he admits that an upcoming audition includes a kissing scene and he has no experience. Tipsy from drinking, Arika impulsively offers to practice with him. The instant their lips meet, an electrifying sense of forbidden pleasure runs through her...