While her husband is away on a business trip, a man suddenly appears at her door—her husband's colleague and someone she once worked with before getting married. The two have plenty to talk about, and he reveals he's getting married soon. However, he lacks confidence in bed and seriously asks her to let him practice using her body. Tsukasa naturally tries to refuse, but as he continues feather-light touches and kisses, her resistance slowly fades. The story unfolds with a gradual, palpable shift in her emotions.