In Beautiful Sunday, there are no good guys or bad guys, only impulses and consequences. Faced with mounting hospital bills for his comatose wife, detective Kang (Park Yong Woo) arranges for a portion of the wares from a drug bust to end up in a rival gang's hands in exchange for a cut of the profits. Kang is willing to do anything to get the money he needs, but the crossed gang is equally determined to recover their stolen goods. In another part of town, Min Woo (Nam Gung Min) and Su Yeon (Min Ji Hye, The Fox Family) meet in a bookstore, fall in love, and get married. What seems like a happy ending derails when Su Yeon discovers that her loving husband is the same man who raped her one night in a dark street. For these two desperate men who have erred in the name of love, crime only leads to more crime as they try to confront their wrongdoings. What happens when their paths cross one beautiful Sunday?