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. But destiny brings the two together when they end up living under the same roof-Kayo (younger sister) as the daughter of a very rich family, and Mayo (elder sister) as the housekeeper. By the time the two find out the truth about their past, they have fallen in love with the same man, Yukio. The drama consists of four parts-the birth of Mayo and Kayo, their lives during high school, reuniting as adults, and five years later. This is an epic spanning 30 years filled with love and hatred.