A young woman Mianhua ("Cotton") gets a job which she has never done before: to be a full-time caretaker of an old stubborn boxer who suffers from Alzheimer's disease. The old man's son with his later wife lives overseas and almost takes no care of him, and his daughter with his ex-wife hires Mianhua to take care of him - but the daughter distrusts and despises all nannies for "knows only lying, abusing, and taking advantages". Under the same roof, however, the old man and Mianhua start to get along with each other well over time, and he starts to mistake Mianhua as his ex-wife whom he owed a love debt to. All of a sudden, Mianhua finds out that she got pregnant...