Growing up, sisters Misaki and Hazuki couldn't have been more different. Misaki's charming personality and popularity stood in sharp contrast to the older, more responsible yet timid Hazuki. After high school, the two lose touch once Misaki leaves their home, only to be reunited many years later, when Misaki returns, harboring a secret.

Sugisaki Momoko used to be a nursery school teacher. Her difficulty smiling leads to communication problems with parents and her contract is terminated in one year. Momoko is picked up by ‘Little Snow’, a home care service for sick children, and makes a fresh start there as a caregiver. When a child has a fever, the caregiver would visit the home and care for the child in place of the parents who simply cannot take time off from work. Momoko encounters all sorts of families at the places she is sent to. With the support of her colleagues and the occasional help of her best friend, Yumika, she starts to face work, romance, family and friendship.

A couple of months have passed since the serial murder case. A new dead body is found in the same area. Detective Manabu Kagaya tries to find the truth. He goes to see serial killer Yoshiharu Urano in prison.