Four adults who have grown wary of love find their lives intertwined in complicated ways. Son Moo-Han is a managing director at an advertising company, while An Soon-Jin, a flight attendant, is living with the pain of unexpectedly losing her daughter. Her ex-husband, Eun Kyung-Soo, has moved on and is now married to Baek Ji-Min, leaving old ties and new relationships to shape their uncertain paths.