Be cautious when telling her to do something.
She does ANYTHING you ask her.

Akari Mita (Nanako Matsushima) is a super housekeeper who perfectly completes everything she is asked to do. However, she never smiles or tries to gain someone's favor. She is always emotionless, and her mind is unreadable.
Mita is assigned to work for the Asuda family. Keiichi Asuda (Hiroki Hasegawa) has just lost his wife in an accident, and his four children, including the oldest daughter Yui (Shiori Kutsuna), are deeply shocked by their mother's death. The family is torn apart and the house was in utter chaos.
One day, Keiichi's sister-in-law Urara (Saki Aibu) plans a birthday party for Asuda's youngest child, Kii (Miyu Honda). Upon hearing Kii's birthday wish to meet her mother, Urara carelessly promises Kii that she will arrange a reunion with her mother. Kii is delighted, but only until her friend at kindergarten told her, "You can't meet a dead person. Your mom is in heaven now, so if you want to meet her, you have to die."
While Kii was walking home along the riverside where her mother drowned, she tells Mita, "Please come with me to meet my mother." Mita's only reply was ... "Certainly."