Yuki's husband is away on a business trip, and she lives with her only daughter, Kana. One morning, Kana asks Yuki, "Can I bring my boyfriend over today?" Yuki is excited to see what kind of boyfriend she will bring over, and she puts all her energy into cleaning. Then, in the afternoon, Kana comes home with her boyfriend, Norihiko. A man and woman of marriageable age...just the two of them in a closed room. Yuki never knew that such a tragedy was waiting for her just a few minutes later. The tragedy that would turn Yuki from a mother back into a woman...