Oh! Brothers stars Lee Jung Jae as Sang Wu, a jaded paparazzi photographer who deals with the less-than-moral side of life. Squeezed for money by a crooked detective, Sang Wu is forced to become a debt collector, a profession he finds little success in. His problems become exacerbated when his estranged father dies and leaves him with a surprise: Bong Gu, his 12-year-old half-brother who looks to be in his mid-30s due to a rapid aging disorder.