How do you go about detaining a total stranger for 12 hours? This is what Ha-young (Lee Yo-won) has to do for her best friend, Mi-ryung (Kim Min-hee). Mi-ryung has been planning for a surprise party for her overseas boyfriend Jun-woo (Shin Ha-gyun), but her plans are stopped short when her father finds out that Jun-woo is half-Hawaiian, and forbids the party from being held. Mi-ryung is put under even greater pressure when Jun-Woo tells her that he would arrive early, and she pleads with Ha-Young to intercept Jun-Woo at the airport, and to keep him from turning up at Mi-ryung's place before she can iron things out.

A dweeby, mild-mannered man comes to the aid of a drunk young woman on a subway platform. Little does he know how much trouble he’s in for.