Hyung Jun awakes one day to find his wife has left him, and he must care for his infant son Sang-ah. This is hard for Hyung Jun, as he thinks cooking, cleaning and a babies are women's work. Left with no choice, he takes his son to work with him, and the office soon gets used to the the baby situation. Hyung Jun gets better at taking care of his son, but when he has to work overtime, the only female employee, Ju Mo, helps look after Sang-ah. The two co-workers become close, but then Ju Mo finds out that that her seemingly perfect boyfriend is jealous. Will she go along with this or break up with him and return to Hyung Jun and Sang-ah?