In a Tuen Mun kindergarten, nestled in a public housing estate, almost half of the 220 children live across the border and spend three hours travelling to and from school.
Despite the long hours, 19 mothers take that journey with their children for a lesson of their own: how to read a storybook aloud to a class.
They want to do their bit teaching moral education at the Yan Chai Hospital Yim Tsui Yuk Shan Kindergarten.
The idea initially was to help children get in touch with their emotions - joy, anger, sadness and fear. "We want to teach the children how to use words rather than actions to express themselves," principal Hilda Pang Mei-ling said.
But understanding that parents were their children's role models, Pang decided to educate them as well by training the mothers to read storybooks to the children, teaching them to dramatise the various characters and to make props.
The 19 mothers who volunteered went through five workshops held by the Hans Andersen Club, a non-profit organisation that trains storytellers. When the mothers were ready for their debut, the Sunday Morning Post sat in on the class of four-year-olds.
Three of the mothers, reading in Cantonese and Putonghua, narrated the story of a dragon that could not control his fiery breath and set his friends and food aflame. The dragon finds himself lonely, until he begins to control his breath. The moral of the story is the importance of anger management.
Lam Tan-ping, a Hongkonger who lives on the mainland for work reasons, told of the time she lost her temper at home. Her five-year-old son said: "Mum, you're going to burn me!"
Pang said the course benefited the mainland parents. "When we tell children to line up, some of them look for the head of the line in order to queue jump. We teach them to look for the back of the queue," she said.
"We find that mainland parents who send their children to study here are eager to adopt Hong Kong practices."
This did not mean mainland mothers needed more help at the school, she said.
"There was a time when we had to teach Hong Kong children not to jaywalk, and they in turn would pull their mothers back from jaywalking."
The Hans Andersen Club received funding from Operation Santa Claus, a campaign organised by the South China Morning Post and RTHK.