Those that have the condition may have difficulty in doing the most basic things, such as taking care of themselves, and need to be looked after almost at all times and places.

In the movie, Kangjian can barely talk. His repetitive knocking on the walls disturbs their neighbors.

On one occasion, Kangjian is woken and frightened by a late-night thunderstorm when his mother has to lock him in and take a part-time job to earn much needed cash. The police and an ambulance are called to check on him and calm him down.

Later when Xiaobei goes to work in a kindergarten where Kangjian has a room to spend the day, the boy is found by other children. Misunderstandings occur and they reach their peak when the boy improperly reacts to an instinct.

China has more than 10 million people with autism. More than 2 million of them are children under 14. The number is growing at around 200,000 a year, according to a 2019 report on development of education and rehabilitation of people with autism.

Sun Menglin, in charge of the report and deputy director of the Autism Rehabilitation Professional Committee of the China Association of Rehabilitation of Disabled Persons, said on the launch of the report on April 2, 2019, the 12th World Autism Awareness Day that the number was a conservative estimate as the diagnosed have mainly moderate or severe cases. Many children with mild symptoms have yet to be diagnosed.