
Contract marriage master Choi Sang-eun's alternate day romance with a long-term mystery client on Monday, Wednesday and Friday and a new superstar client on Tuesday, Thursday and Saturday.

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...

Sang-eun's hurt by Ji-ho asking to end the contract first. She delays it giving a flimsy excuse. She's strangely upset with him and is confused by it. Meanwhile, Hae-jin sees his first love Sang-eun who disappeared 13 years ago after leaving a strong impression but is shocked she is Ji-ho’s wife. To make the matters worse, he witnesses Ji-ho’s strangeness and believes that she is in danger...

Sang-eun, Ji-ho and Hae-jin have a three-way encounter at the mansion. Ji-ho reveals his identity to Hae-jin due to his suspicion. Sang-eun gets to know Ji-ho a little bit more but despite what she wants the time for to end the contract comes. When the contract ends, restless Sang-eun visits Ji-ho with divorce papers as an excuse to see him but is attacked by a mysterious armed-man...

Sang-eun's surprised at Ji-ho giving her concert tickets, not divorce papers. They extend their contract as they run into his senior judge and his wife. Madam Yoo is in big trouble after seeking a comeback after losing everything 13 years ago due to Sang-eun. Sang-eun saves her and give up her retirement despite her love-hate relationship. Meanwhile, Hae-jin gets into trouble from a false rumor...

Sang-eun is angry at Hae-jin. Hae-jin asks Sang-eun to take him as her customer. She is torn seeing him vulnerable and eventually, she accepts his offer. Ji-ho feels uncomfortable about their contract. Sang-eun tries to clear up the misunderstanding but is not easy. Meanwhile, Madam Yoo is released from the detention center and stays at Sang-eun, and their uncomfortable living situation begins...

Sang-eun needs to settle a contract with Hae-jin. After some quarreling, Ji-ho's day is Mon, Wed, and Fri and Hae-jin on Tues, Thur, and Sat. And the alternate day marriage begins. Meanwhile, Sang-eun and Ji-ho prepare a housewarming party for his work. While decorating the house they develop feelings. At the housewarming party, Sang-eun drinks too much and gets a serious blackout the next day...

Sang-eun remembers her first kiss with Ji-ho but is upset as Ji-ho seems indifferent. They hide their feelings causing their relationship to be awkward. As Hae-jin uses work as excuse and goes on a date with Sang-eun, he’s feelings towards Sang-eun grows even more. Meanwhile, Madam Yoo visits Ina group and threatens to take back Sang-eun into their family again…

Ji-ho tries to find a way to express his feelings toward Sang-eun. During a couple’s golf gathering, he doesn’t hold back to show kindness and care towards Sang-eun causing her to have mixed feelings about him. Meanwhile, Hae-jin happily waits for Tues, Thurs and Sat but gets into a big fight with Ran-hee who questions about Sang-eun. He then collapses in front of Sang-eun due to extreme stress.

Sang-eun meets Ji-eun, ex-wife of Ji-ho and a legal advisor of Hae-jin. Ji-ho says no more than there’s nothing between them but Sang-eun’s thoughts gets tangled. After filming, Hae-jin misses Sang-eun and visits her but drunk Ji-ho appears and three of them have an awkward gathering at the beach. When Ji-ho witnesses Hae-jin and Sang-eun being close, he appears to be bothered for the first time…

Ji-ho and Sang-eun realized their feelings for each other and he surprises his co-workers by coming to work very differently than usual. Sang-eun tries to end the contract with Hae-jin to focus her relationship with Ji-ho and Hae-jin tries to give up his feelings for her but finds it difficult. Meanwhile, Ji-eun finds out Sang-eun had contracts with both Hae-jin and Ji-ho and visits Ji-ho’s house…
Created by: nam seong-woo, Jung Yeo-jin, ha goo-dam
Available on: tvN