A female high school student named Sayaka kills herself, but the reason why she killed herself is unknown. Sayaka appeared to have a normal life with her family, including her mother Rumiko. Rumiko seemed to raise Sayaka with love and care. In reality, Rumiko is a mother who is unable to give love to her daughter and Sayaka is a daughter who wants to receive love from her mother.

When mother Rumiko and daughter Sayaka think of the same incidents that took place in the past, they tell different stories.

Adapted from the novel "Bosei" (母性) by Minato Kanae (湊かなえ).