Dr Elsie Tu, who turns 100 today, is the co-founder of the school, and was the driving force behind the establishment of the Independent Commission Against Corruption (ICAC).
Murray MacLehose, the former Governor of Hong Kong from 1971 to 1982, once said to Tu that she was the one who "pushed my elbow" in the implementation of welfare reforms which became instrumental to the development of Hong Kong.
Born to a working-class family in Newcastle, Britain, in 1913, this incredible lady was an all-rounder at school, excelling in academic studies as well as sporting endeavours.
After graduating from Durham University (where I am currently studying) in 1937, she was a school teacher for 10 years before traversing the Indian Ocean and arriving as a missionary in Nanchang, in China's Jiangxi province, in 1948.
With the political situation in Communist China particularly volatile, she travelled to Hong Kong in 1951, and the city has been her home ever since.
Counter to her expectations of a British government promising British justice and democracy to the people of Hong Kong, she was shocked to discover a society infected by corruption, poverty, and an apathetic colonial government.
"I was a Briton in a British colony and I was ashamed of what the British were doing," Tu says.
Spurred on by a relentless zeal to help people in need, the warm-hearted missionary went from distributing clothing donations to the poor to being an urban councillor in 1963, and later a Legislative Council member in 1988.
She prides herself in drawing the government's attention to the problems of the poor.
"I used to get 50 to 100 people coming to see me every week [to tell me about their problems]," she says. Then she would go and see the problems for herself.
But reform was difficult, she says, because the government wanted to turn a blind eye.
"For example, one day I saw some people cooking food at the emergency exit of a cinema," she says. "I took photographs of the scene with a policeman watching and doing nothing about it."
She then showed the photograph at an Urban Council meeting.
"But in the next meeting, the government brought along another photograph, with no one cooking food there. They said I was telling lies, when they had evidently taken the photo after moving the people out."
Corruption back then was a serious roadblock to reform. But, says Tu, "I felt strongly that no matter what, I would fight on".
Tu's happiest and proudest achievement is Mu Kuang. After a series of riots in 1967, she was called upon by the government to set up a school for the underprivileged in Kwun Tong. Her commitment to the cause, however, dates back to her very first school in 1954, which took the form of a tent.
"Every step forward in the building of the school is a happy memory," she says. "Education is very important because if young people do not receive an education they have to find something else to fulfil their wishes and ambitions. If they can't fulfil their ambitions legally, they may be tempted to do something illegal. I think that's why, at that time, we had so many triads."
Her advice to young people is to protect their health by keeping away from harmful things like drugs and to work hard.
Today, Tu's sense of justice and responsibility for the poor is still alive in her slightly croaky but confident voice.
She only hopes our generation will make a difference to a society which has plunged into a state of severe economic inequality.
We wish Dr Tu a very happy birthday!