Sung Soo-mun was born in Seoul, South Korea in 1992. His early life could be considered fairly normal, spending most of his time at school or playing outside. His father worked as a businessman with a tech company, and his mother stayed at home to take care of him and his sister. Sung Soo-mun's father died in 2009 of a heart attack, forcing him and his mother into work to provide for themselves and Soo-mun's sister. While his mother quickly found work at a local gas station, the meager pay was barely enough to provide for the three of them. Soo-mun started working as a freelancer, travelling from city to city and picking up odd jobs wherever he could find them. The combined salaries of Soo-mun and his mother allowed the family to barely scrape by in their average Seoul apartment. In 2013, his mother was involved in a car accident and died shortly after. Sung Soo-mun sent his sister to live with their deceased mother's family, and sold their apartment and belongings to start a new life. He managed to travel to China, continuing his work as a freelancer before moving on to Chernarus to work at a factory. Soo-mun found himself trapped in Chernarus when the city was quarantined in 2014. Now he wanders around, trying to get back to his sister should she still be alive.