Seoul, South Korea (CNN) -- Choi Sung-Bong is polite and serious. The 21-year old star of reality TV show "Korea's Got Talent" hardly ever smiles. Little wonder when you realize how life has treated him so far.
Left by his parents in an orphanage aged three, he ran away at the age of five as he was being bullied. Choi tells CNN, "If a little kid is being abused, the only thing he can think about is probably to get away from that situation. My life changed then."
For the next 10 years, Choi lived on the streets, sometimes in a container box in the red light district of the city of Daejun, sometimes in night-club stairwells or public toilets. He survived by selling gum and drinks in bars and clubs. "Some people would buy gum," he said, "but some would hit me over the head with a beer bottle or punch me. I lived like that from day to day."
Choi says local criminal gangs did not want him selling gum in the area and once grabbed him and took him to a nearby mountain. "They dug a hole, threw me in it and buried me."
If Choi feels anger for what he has been through, he does not show it. He thinks long and hard before answering a question and even apologizes for not being able to better express his thoughts.
"My life was meaningless," he continues. "There was only one thing that gave me comfort. It was music, not people... I felt calm when I listened to music... music was my only friend when I was lonely."
Hearing an opera-style singer in one night-club, he knew that's what he wanted to do and searched the internet for a teacher. He found former opera singer Park Jung-So. Park tells CNN he couldn't believe Choi's story so went to see for himself.
"He was living in a container box with no running water, electricity or heating. He said he slept there with layers of clothes on in the winter." Winters in Korea are harsh and often well below freezing.
"His situation was unbelievably harsh but his passion for music, for wanting to learn, was very strong," says Park, who instantly started training him free of charge. He also helped him pass the state examination and he was accepted at an Arts High School at the age of 16.
Park says he found it difficult to interact with the other students there as he was so used to being on his own. "He was taken advantage of so often, people would pretend to help him but would deceive him. He became wary of people."
Park put Choi in touch with a children's foundation, Child Fund Korea, and social worker Yu Hyun Jeong took on his case. "Through us, he was able to have a place of his own, a government subsidized place. And because he was studying music we helped him go through school."
But Yu is concerned about how Choi will cope with his life changing so fast. "On the one hand, I really hope he is successful but on the other hand, I'm very worried that he might be hurt by all this somehow... all this overwhelming interest might be too much for someone who's been abandoned all his life."
Choi says he did try to kill himself a number of times in the past and believed he should never have been born. After coming second on "Korea's Got Talent," he now says he has something to live for and hopes his music can give hope to others in the same position as he was.