崔尚恩為需要結婚的單身人士提供定制婚約。做了13年的結婚生意，她想退休，但卻發現很難結束她與在周一、三、五見面的長期客戶，鄭智鎬的關系。他們已經在一起五年了，但她對他一無所知，並推遲結束他們的合同。與此同時，超級明星姜海鎮搬進了智鎬家樓上......

尚恩、智鎬和海鎮在大宅裡發生了一場三人的邂逅。由於海鎮的懷疑，智鎬向他透露了自己的身份。尚恩對智鎬有了更多的了解，盡管他們的合約快結束了。合約結束後，不安分的尚恩以離婚協議書為借口去看望智鎬卻被一個神秘的武裝分子襲擊了......

當智鎬把音樂會門票而不是離婚協議書交給尚恩的時候，尚恩感到十分驚訝。由於他們碰到了他的高級法官和他的妻子，他們延長了合同。劉女士在十三年前因尚恩而失去一切後尋求復出，陷入了大麻煩。尚恩救了她，並不顧她的愛恨情仇放棄了她的退休計劃。與此同時，海鎮因一個虛假的謠言而陷入困境......

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…

Sang-eun worries about Ji-ho as she is exposed to the public. Ji-ho’s senior informs about his promotion but doesn’t tell Sang-eun. Sang-eun tells Gangjin group’s family she doesn’t want to marry Hae-jin. Ji-ho makes questions for Sang-eun and they have a great time. While Hae-jin’s at the police station due to his clash with Sang-eun’s stalker. Sang-eun’s in shock when the stalker is revealed…

Sang-eun’s 12th marriage is unveiled causing controversy and she insists she’s at fault to protect Hae-jin. She asks Ji-ho to have some space due to this. Ji-ho and Hae-jin is upset seeing Sang-eun trying to bear everything. Ji-ho hears from Gwang-nam of Madam Yoo’s provocation to Sang-eun and investigates her and Ina group. Hae-jin prepares a conference to squelch criticism towards Sang-eun…

Sang-eun rushes to the hospital in shock when she hears of a mysterious car accident. Ji-ho comforts her and they become closer. Hae-jin makes a formal announcement of his breakup with Sang-eun. Chairman Ganjin tells him to join Gangjin group. Seon-jin feels threatened and uses Sang-eun to ingratiate himself with his father. Meanwhile, Ji-ho questions the car accident and starts investigating…

Sang-eun looks for what she wants to do after her retirement and Ji-ho supports her. Hae-jin enters the Gangjin group where he shines causing a conflict with Seon-jin. Sang-eun visits Hae-jin as she’s worried about his sudden retirement but Hae-jin purposely acts distant towards her. Meanwhile, Sang-eun finds out that Ji-ho met Ji-eun to grant her a wish causing them to have a lover’s quarrel…

While Sang-eun and Ji-ho have a lovely time dreaming of their future together, people ordered by Seon-jin secretly break into Sang-eun’s house. Hae-jin learns of this and tells Madam Yoo of Seon-jin’s scheme to use Project Jamie. Madam Yoo decides to take all the blame to protect Sang-eun and Ji-ho goes against his principle for the first time to stop her…

After that day, Ji-ho waits for Sang-eun who didn’t turn up. Sang-eun doesn’t have the courage and hesitates and Ji-ho returns to his cold self. The co-workers become more worried seeing Ji-ho being so emotionless. Meanwhile, Sang-eun realizes her feelings through honest advice from Gwang-nam and Madam Yoo…