Risako Yamazaki lives with her 3-year-old daughter and husband. She is informed that is selected as an alternate lay judge in a criminal case. The defendant in the case is Mizuho Ando, who is also a housewife and about the same age as Risako. She is on trial for drowning her 8-month-old daughter in a bathtub. Risako feels hatred to Mizuho, but after the trial begins, Mizuho's situation reminds Risako of her own past memories.
