In Ji works for a contract marriage provider in NM. The company provides its clients with a spouse for a fixed-term 1-year contract marriage. In Ji has finished her 4th contract marriage. She meets Jeong Won for her 5th contract marriage. Jeong Won works as a music producer. His life is filled with anxiety and loneliness due to the pain from his past. He still badly misses his ex-wife, Seo Yeon, who applied for the spouse-providing company NM for him.

Jeong Won meets In Ji from NM, and he begins his second marriage with her. They get to know each other and get used to each other as time passes. One day, a mysterious trunk is recovered from a lake. This leads them into a whirlwind of secrets behind the NM company.