Kyoko is a nurse who is betrayed by her husband, Toyoki. She is so furious that she kidnaps Mayo, the baby born between Toyoki and his girlfriend Tokiko. Kyoko decides to call the baby Botan and starts raising her in secrecy. The couple is broken-hearted, but the following year, Tokiko gives birth to a baby girl whom they name Kayo. They devote themselves to loving the child and try hard to forget their sad past. Consequently, Mayo and Kayo grow up not knowing about each other.