The 18-year-old forward always steps up to take penalties - and takes them with nerves of steel. Pressure doesn't faze him.
Yet his confident playing style belies real life. Off the pitch he is just a normal teen with his own problems.
"My family had a financial crisis last year and I had to take a part-time job. My goal was clear: take good care of myself and try to become financially independent. Any leftover money I would give to my parents," he says.
Chun-yin took a job at a newspaper company. That wasn't an easy task.
"I had to commute to an industrial estate and start work at 11pm every day," he recalls.
"My job was to pile up printed newspapers into stacks and load them on to a delivery truck."
His shifts lasted until 5am. After a quick nap, he was off to school.
"Sometimes I was just too tired and didn't have the energy to attend lessons," he says.
"Some days I only finished work at around 7am. I couldn't even get to school on time."
In the afternoon he would sleep for five hours before going off to work again.
"When there was a football practice session after school, I would only have two hours of sleep."
His punishing schedule had an impact on his game, the forward concedes.
"It was hard for me to keep my fitness up, but I had no regrets about my packed schedule: this is what I had to do, so I did it," he says.
The Form Three student from YCH Tung Chi Ying Memorial Secondary School kept details of his adversity to himself. He didn't discuss them with his teachers or friends.
"I know they care about me, but I did not want to worry them," he explains.
Fortunately, by last November things began to turn brighter again for Chun-yin. His family's financial problems eased up. He sees that as a victory for his parents, his elder sister and himself.
"There are many family tragedies in Hong Kong for all sorts of reasons," he says. "But our family pulled together during our crisis and we each did our part to make things better."
Gone are the days of working late into the night, but Chun-yin learned a valuable lesson. "I know I should spend my money wisely. I can tell you that I won't be spending HK$30 on an ice cream or drink again," the student notes. "That's what my hourly wage was. I learned to be better with money."
Now Chun-yin is facing new challenges - on the pitch. Last April he spent 10 days at a training camp in Spain. His expenses were covered by the professional footballer preparatory programme co-organised by his school and Kitchee Sports Club.
"I could play football in Spain without adding to my family's burden. I was lucky to have this chance to enhance my skills with my teammates," he says.
The young footballer is looking forward to playing at the All China Secondary School Students Games in Inner Mongolia in July.
"I am on the final training team list and waiting for my participation at the Games to be confirmed. I would really like to play for Hong Kong," Chun-yin says.