Choi Sang-eun gives customized marriage contracts for singles needing a marriage. After 13 years in the business, she wants to retire but finds it hard to end it with Jung Ji-ho, a long-term customer of Mon, Wed, and Fri. They’ve been together for 5 years, but she knows nothing about him and delays ending their contract. Meanwhile, superstar Kang Hae-jin moves in the top floor of Ji-ho’s house…