Okano Kuang (Gao Liang Jianwu) is determined to become a teacher who preaches and teaches. After completing the relevant study, he entered Yingqiu Primary School and began his teaching career. Two years later, the once hot ideal is still fresh in my mind, but the pale reality always reminds Okano that he seems to be farther and farther away from his ideal. Her husband is on business, and the young mother Yamei Mizu (Makiko Ono) is raising her three-year-old daughter alone. In the eyes of outsiders, Yamei is a perfect mother. She is patient, gentle, cheerful and kind, and gets along very well with other mothers. However, whenever I got home, whenever my daughter did something wrong or just disliked her, the angry punches would fall mercilessly on the child's small body. Once upon a time, Yamei was also the culprit of domestic violence, but now her identity has changed, but the tragedy has happened again.