The day Wing's mother started work as a part-time waitress was his first experience of being left home alone. It was winter last year; he was eight years old, and his brother, Han, was just three.
'I was scared and stayed in bed. I was afraid someone would call the police and catch me for staying home alone,' Wing recalls. 'I waited for a long time and kept wondering when my mother would return.'
The two brothers must fend for themselves whenever their mother is at work. If they are hungry, Wing cooks instant noodles on the electric stove in the tiny cubicle that his family rents in Sham Shui Po. They go to bed on their own.
Hong Kong's home-alone children are a growing, although largely hidden, problem. They often come to light when the absence of adult supervision results in an accident in the home or a tragedy, for instance, when curious youngsters fall out of a window.
The number of cases in which police were brought in has doubled from 35 in 2007 to 60 last year. The number of new child neglect cases filed with the Social Welfare Department has also risen to 113 last year from 22 in 1996.
However, such reported cases are probably just the tip of the iceberg, social workers say.
'The problem is hidden. Most parents will not disclose that they leave their children alone at home for fear of arrest,' says Susan So Suk-yin, director of the Hong Kong Society for the Protection of Children (HKSPC).