Bowing three times in front of a huge portrait of Mr Deng, these children were mainly from Hong Kong's "leftist" schools, set up in the 1940s and 50s by Hong Kong intellectuals who sympathised with the Communist cause.
In the 1960s and 70s the leftist schools were very militant, taking an active part in riots instigated by Red Guards trying to destabilise the Colony. For a long time these schools were treated with suspicion by the Colonial administration.
As the June 30 handover to Chinese rule approaches, these schools are proudly and openly parading their allegiance. The teachers, many graduates of the same schools, no longer face discrimination in job hunting and the principals are sought-afte r by other schools hoping to understand how "patriotic" education can be implemented.
Tsang Yok-sing, principal of the Pui Kiu Middle School since 1985 and the chairman of the pro-China political party the Democratic Alliance for the Betterment of Hong Kong, is in demand as a guest speaker. He says the Colony's six leftist schools, apart from raising the Chinese flag at assemblies and reading pro-China newspapers, are not as distinct as they once were.
"It is not so much that the pro-China schools are losing their former characteristics and forgetting about their pro-Communist goals. Other schools are catching up. They are also organising trips to China. We are by no means unique in educating our students to be proud of being Chinese."
Communist ideology changed under Deng, becoming more pragmatic than during the Mao era. Staff of pro-China organisations in Hong Kong who were once obliged to send their children to leftist schools had greater freedom to send their children to mainstream schools
Graduates of the leftist schools found it difficult to get into government jobs in Hong Kong, and were excluded from teacher training colleges. Enrolment dropped off because parents were worried about the quality of staff as teaching increasingly became a graduate profession. After the fervour of the Mao era, Communist teaching was no longer attractive to parents.
Leftist students make up less than 2 per cent of Hong Kong's student body but the stigma is fading, some even believe the leftist schools will have a privileged position after the handover. "We are not expecting our students to be specially favoured (by the Chinese rulers) after the handover because of their education. But it will be a more level playing field," says Mr Tsang.
Few former pupils of leftist schools are prominent in China's handpicked team of people who will run Hong Kong after the handover, as China has preferred experience over blind loyalty. Nonetheless the spotlight is on the leftist schools to lead the way.
The Mongkok Workers' Children's School established by left-wing unions through public donations in 1946, raises the Chinese flag every day and the Chinese national anthem is played. These activities, which may once have been regarded as quaint, or slavishly nationalistic, are being watched closely by other schools aware that China will impose more patriotic education on schools.
"Teachers in Hong Kong are worried about patriotic education," says Mr Tsang. "Their impression is that the Chinese government is oppressive, that there is a great deal of indoctrination, and little freedom of speech and thought. They believe they can easily get into trouble if you do the wrong thing. They want to see how we do patriotic education,so that they can get it 'right'."
But even Tsang believes patriotism is not as simplistic as it once was. Teachers need to get students better acquainted with China to foster a more positive attitude. "Under the Colonialist education system absolutely nothing was taught about China. How can you promote a sense of belonging under such a system? The leftist schools were different because they always had links with the Mainland."