A young man discovers that the woman who raised him is his stepmother. His stepbrother, who is unaware of the revelation, resents his mother for always punishing him more severely than his stepsibling.

The story focuses on the widower Nemoto, ostensibly a businessman, who has one son, Kanichi, the hero of the title. Nemoto remarries; his new wife is a widow with a son and daughter of her own. However, Nemoto’s business turns out to be out a shady scam, and he disappears, leaving his wife to raise the three children alone. In order to support the family, she is obliged to become a bar hostess. She conceals this shameful employment from the children, but the truth comes out years later, after her daughter is rejected by her husband’s family when they investigate her background.

An unemployed Japanese man and his two sons wander the industrial flatlands of Depression-era Tokyo, until he chances upon an old friend and befriends a woman and her daughter, who are in a similar predicament.