Shu spends his days out at night with his delinquent senior, Abe. One day, his mother Miyuki, hoping to reform her son, begins drinking sakazuki with him. In this loving family moment, the two become pleasantly drunk and cross into forbidden territory. Though realizing it's wrong, Miyuki gives in to Shu's long-suppressed feelings for her, revealing the tragic nature of a woman's desires. Meanwhile, Abe, who has a strong attraction to mature women, sets his sights on the Kobayashi household.