Noh In-ji works at the matchmaking company NM, which matches people together and immediately gives them a contract that makes them married for one year. Noh In-ji has just completed her fourth marriage and meets musician Han Jeong-won for his second wedding. However, Jeong-won is still struggling with the breakup of his first wife. But one day, a mysterious suitcase is found in a lake, which threatens to expose many secrets about NM.