Things are looking bleak for average Joe salaryman Hyung Joon (Choi Min Soo) when his unsatisfied wife suddenly walks out on him, leaving their helpless baby in his not-so-capable hands. Having no one else to turn to, Hyung Joon takes his baby to work, creating pandemonium at the office. But as time passes by, people in the workplace become accustomed to having the little tot around - even the self-proclaimed, baby-loathing female colleague Young Joo (Choi Jin Sil). Initially apprehensive of the whole "office baby" hoopla, Young Joo slowly loosens up, eventually forming a special bond with the baby and his goofball daddy.