Huynh Quang Khai, the founder of the class, has spent the last 10 years teaching poor students.
Despite having no training as an educator, Khai, a freelance tour guide, teaches children who can't afford formal schooling.
Rain or shine, the children come to class to learn from Khai every day.
With just a few students in a makeshift tent in the beginning, Khai now has about 60 students aged 8-19.
His students come from poor families struggling to make ends meet, so they have to help their parents earn money during the day and can only go to class in the evening. Some of them suffer from birth defects so teachers must be patient when teaching them.
When asked why he teaches the kids, Khai said in 2008 he saw many children in the neighbourhood could not read or write.
He decided to teach them. Khai and his friends went to areas with a lot of children selling lottery tickets. They talked with the children and encouraged them to join a class of about 10 students.
“My father died when I was a small child so I understand the sorrow of lacking a father’s love.
“Seeing my friends being picked up by their parents made me sad. That’s why I consider these children as my kids. I’m afraid that they will face many challenges in life if they are illiterate,” he told e-newspaper Zing.
Khai said because his family was poor, he had to do different jobs including selling lottery tickets and working at restaurants or food and garment companies to pay his college tuition fees.
In the past, he worked for a tourist company but he quit the job as he feared no one would take care of the class while he was away.
Now that he works as a freelance tour guide he is more flexible and only works when someone can take over the teaching.
In addition to teaching maths and literature, he also shares his life experience with students and answers their questions.
Despite struggling with their own hardship, Khai and his wife have always strived to make students feel comfortable at the class.
The couple even had to sell their wedding presents to build a new classroom equipped with a whiteboard and television.
Khai also organises field trips for the students.
He tosses and turns many nights worrying about how to keep the class going.
He tries to encourage the students coming to class and convince their parents of the importance of learning.
The two criteria students have to fulfil before being admitted to his class are being older than eight years old and a desire to learn, Khai said, adding that he didn’t admit children at 5-6 years old because he feared some parents would send their younger kids to him instead of primary school to save money.
“My family has just moved to the city. Because my parents can’t afford to send me to school, I'm studying here. He takes really good care of us,” said 13-year-old Khanh Ly.
“I hope that I will be a teacher in the future so I’ll teach children in difficult conditions like our teacher Khai”, she said.
Giang Thi Ngoc Diem, 12, who has been learning in the class for more than a year, said: “I like going to the class very much. I often come early to play with my friends. The teacher is strict but very kind to us and really good at teaching.”
Khai said what makes him proud was that many of his students have gone on to success after graduating.
“On the New Year and Vietnamese Teacher’s Day, some of my old students visit my house and that makes me feel glad.”
“I have not attended any teacher training class. I teach them what I learned. I teach the students with all my effort.”
“I just think when I am young I will strive to do something to make society better,” he said.