When Shanghai was put under lockdown due to a severe COVID-19 flare-up in April, many residents resorted to group purchases for daily necessities. Among the numerous coordinators of these purchases, one young man caught people's attention for showing maturity beyond his age.

Cai Hanxiao, 17, is a second-year high school student living in the city's suburban Qingpu district. During the outbreak, he voluntarily took charge of group purchases for the residential community he lived in, helping more than 600 people obtain daily supplies.

For this he was hailed as the "youngest head of group purchases in Shanghai".

In a clip published on video-sharing platform Bilibili in April, he shared his experience as a group buying coordinator.

Cai said after the residential compound was put under lockdown, like everyone else he had to cook himself. After only a few days, he ran out of fresh vegetables.

Cai posted a massage in a community chat group to find residents who also needed vegetables. After some answered his call, Cai created a new group for collective purchasing.

His first try was not successful. After collecting 30 orders – the minimum required for a delivery – Cai contacted a nearby supplier. However, the supplier refused to deliver the goods on the grounds it was in another town and its priority was to serve residents in its own area.

Cai did not lose heart due to the setback. The next day, he pooled together 80 orders and negotiated with a supplier. A deal was made, and the vegetables were delivered to the doorsteps of residents the following day.

"I was very excited when I received the first batch of vegetables," Cai said.

Then, more residents joined Cai's group, and demand grew rapidly. At that time, people didn't know Cai was a teenager but still put their trust in him. The goods on his purchase list expanded from vegetables to meat and milk.

The young man admitted at first, organizing group purchases affected his studies. But later he optimized the work flow and started using a mini-program which enabled people to sign up for a group purchase automatically, which saved a lot of time.

Cai revealed his experience as head of the student union of his school has helped cultivate a sense of responsibility.

"[In school] we organized many activities, big or small. If anything went wrong, I would be held accountable. For the duty that I shouldered [as a group purchase coordinator], I did not worry a lot. I thought it would not be a problem," he said.

According to Cai, some neighbors were rather surprised after learning he was a high school student.

In the video, Cai said he wanted to show people a different aspect of high school students.

"I want to show you high school students are not nerds that know nothing but how to solve problems on exercise books. We can help people solve practical problems in real life."

"For me, the experience as a group-purchase coordinator serves as a vivid case of social practice. For the first time in my life, I have learned what society is really like," Cai said.

One thing he learned is people are different. "Some things you don't need are maybe necessities for another," he said.

Cai said he ordered seafood twice, to help a man who didn't eat meat due to his religious belief. He had previously been relying on adult milk power as a source of protein, and it was running out.

The young man said the residential community he lived in is a rather high-end one, and he used to believe people living there were all rich until he met an elderly woman who bargained for almost everything she bought.

Later, Cai learned the woman's life was quite difficult: she lived on a pension of only 3,000 yuan ($447) a month, of which half was given to her son, who was debt-ridden after a business effort failed.

"That's when I understood why she would bargain over a bottle of milk worth 30 yuan," he said.

Speaking of his experience as a group purchase coordinator, Cai said: "Looking back, I don't think it was a tiring job. I feel happy because I could help others."

"I don't think I have done something extraordinary. I am satisfied with myself because I did not hesitate to take responsibility when others needed me, and did what I should have done."