It's not uncommon to see teenagers or even adults fighting in public - on their handheld electronic games and on the internet. But even in the electronic age, we see some old toys making a comeback.
Wyman Chan Man-fai and Benjamin Chan Chun-man are both yo-yo addicts. Wyman has been playing for 10 years, while Benjamin started seven years ago. They are both members of the Hong Kong Yo Yo Fan Club.
'There are about 30 yo-yo tricks, 10 in each of the difficult, medium and easy level,' Wyman said. 'I have mastered them and now I perform them.'
He has been invited by numerous yo-yo companies to perform in countries including Australia, New Zealand, South Africa, on the mainland and in Taiwan.
Wyman, 22, said it was also great fun to show off his tricks to other yo-yo fans.
Members of the Yo Yo Club gather every Sunday at the open area outside Sha Tin Town Hall. There are more than 1,200 members mostly aged between 12 and 20 with the youngest just seven years old.