Oh Gyu Tae was an amateur boxer until high school, he gave up on pursuing a sports career after his older brother’s mysterious suicide. He studied ardently, graduated top of his class at the Judicial Research and Training Institute. He subsequently became a promising prosecutor in an investigative department. During a troublemaking heir's assault trial, unable to contain his anger, he brought a law book down upon the heir's head. He was forced to retire and had his license suspended for ten years, thus ending his career in the legal profession and leading him to make a meager income working part-time at a friend’s auto-tuning shop.