Beautiful mother aoi lives happily with her son but feels lonely due to her husband's long-term absence overseas. One day, her son's best friend yuu comes to stay for a club activity. Yuu, who has had feelings for aoi since childhood, suddenly kisses her. Despite herself, aoi feels her heart racing. Later, yuu presses her again, and aoi, whose lips are stolen once more, finds her suppressed infidelity desires ignited.
