The father of the three daughters, Sachi, Yoshino and Tiki, left them for another woman when they were still children. Their mother, unable to bear their father's infidelity, also left them. Sachi's older sister was left with no choice but to become the head of the family and take care of the younger ones, even though she was still in high school at the time. After 14 years, their father dies, and the three sisters come to the funeral. There they meet their half-sister, 13-year-old Suzu. Suzu's mother has long since died, and after her father's death she is left with her stepmother and estranged brother. The sisters invite Suzu to come and live with them.

Jerry Blake embodies all the dreams of single moms. He is handsome, smart, kind, and madly in love with children. Every woman wants to lean on his strong shoulder and let him run her own life. Despite the huge list of merits, Jerry is a deadly danger to others. He's been floundering for a long time in search of the perfect American family. And every time disappointment befalls him, he ruthlessly kills all his housemates. After one of these cases, Blake moves to another city, where he finds himself another test subjects. So far, the new house is calm, but his stepdaughter proves to be too curious.

A well-to-do English family hires an American nanny for their son. Arriving at the new place of work, the nanny discovers that her ward is not a real boy at all, but a human-sized doll, which is treated as a living person. But disturbing events that occur after the nanny breaks the rules make her believe that the doll may actually be alive.