Once a promising athlete, Yoon-Bin is ready to give up after repeated injuries shatter his dreams. At his lowest point, a mysterious man with a tiger tattoo gives him the strength to stand again. Years later, after retiring as a gold medalist and becoming a taekwondo instructor, Yoon-Bin unexpectedly reunites with Kwon Young, an underworld boss and the man who saved his life. Haunted by his past, Young pushes Yoon-Bin away, convinced he brings only harm. But Yoon-Bin refuses to let go, because now it is his turn to become Young’s light.