Seok Moo is a very picky and sensitive man. Hwi Roo is a relaxed and positive woman. These two completely opposite people got married for 3 years, but they still quarrel over every single thing. During a tough day at work, Seok Moo happens to meet his ex-girlfriend.

Suk Moo and Yoo Young go out for dinner together, and Suk Moo tells her about how he met and married Hwi Roo. Hwi Roo sends a text to Suk Moo as a suspicious guest arrives at her guest house. However, Suk Moo is too busy with his own business to realize that she really needs him.

Suk Moo runs into Jang Hyun on the street and ends up going to his grandmother, Mi Sook's cafe. Suk Moo gets to talk to Yoo Young again. Meanwhile, Ma Roo tells Suk Moo where Hwi Roo is, and Suk Moo heads to Hwi Roo's hometown.

Suk Moo and Hwi Roo visit Suk Moo's father, Koo Ho's birthday party. After having a birthday party, Suk Moo and Hwi Roo head to Suk Moo's grandmother, Mi Sook's birthday party as well. Meanwhile, Suk Moo sees Jang Hyun with another woman and tells Yoo Young about it.

Suk Moo is shocked to realize that Yoo Young had no happy memories with him. At home, Suk Moo and Hwi Roo argue again over petty things, so they end up deciding to put up some rules to follow. They try to show each other that they’re having a fun time by their own, and it leads to a childish fight over social media.

Suk Moo hurts his back while trying to help Ma Roo. Jang Hyun helps him get home, but they find that Yoo Young and Hwi Roo were having a chat together at Suk Moo’s house already. The two couples talk together about each other’s relationships, and they all get shocked after hearing why Yoo Young broke up with her ex-boyfriend.

Suk Moo feels terrible after hearing what he had done to Yoo Young so many years ago. He wonders if Hwi Roo decided to divorce him because of the same reason. Hwi Roo goes out to watch a movie with Shi Ho and realizes how Suk Moo must’ve felt. Meanwhile, the real estate agent calls Hwi Roo and tells her that they’re coming to see the house.

Hwi Roo tries to tell Mi Sook that she and Suk Moo are getting divorced, but she fails to do so. Tae Hyun gets an aloe from Hwi Roo and prepares dinner to thank her, but Hwi Roo goes out as soon as she comes home that day. They end up arguing again, and Tae Hyun feels sorry for Hwi Roo. However, things only get worse.

Suk Moo goes out to find Hwi Roo, and he sees that she met with Yoo Young. He keeps watching them but ends up losing control of himself once he sees some guys hitting on both Hwi Roo and Yoo Young. Meanwhile, Yoo Young calls Suk Moo and tells him that someone ran away after breaking her window.

Jang Hyun confesses to Suk Moo that he didn’t hand in the marriage registration and Yoo Young knows nothing about it. After another day of work, Suk Moo returns home and sees that the man Hwi Roo has been meeting was Shi Ho. He goes out for a walk out of frustration and comes across Yoo Young again.

Suk Moo and Hwi Roo hand in their divorce application and try seeing each other as strangers. Hwi Roo’s dad gets hospitalized at a hospital in Seoul, and everybody gathers there. Meanwhile, Suk Moo tells Jang Hyun that Yoo Young knows about the marriage registration now.

Suk Moo’s family and Hwi Roo’s family gather together to get a family photo. Suk Moo’s grandmother sees that Hwi Roo has brought Shi Ho home and overhears that Suk Moo and Hwi Roo has gotten a divorce. Meanwhile, Hwi Roo changes her mind and tells Jang Hyun that they should go camping together.

Suk Moo and Jang Hyun find the girls having a party. Suk Moo, Hwi Roo, Yoo Young, and Jang Hyun decide to go on a trip together. Mi Sook realizes that Suk Moo and Hwi Roo were trying to sell their house. Meanwhile, Soo Kyung’s friend visits the Mi Sook’s restaurant to see Soo Kyung.

A newlywed couple make a mistake and think Suk Moo is with Yoo Young while Jang Hyun is with Hwi Roo, so Yoo Young and Hwi Roo each talk about their good and bad traits. Suk Moo catches a cold after sleeping in the tent. Jang Hyun suggests going to a hotel for their second night. Meanwhile, Suk Moo and Hwi Roo get into a heated argument after getting drunk.

Suk Moo and Hwi Roo are shocked to realize what they did last night after getting drunk. Jang Hyun ends his relationship with other women and prepares himself to concentrate on Yoo Young. Meanwhile, Jang Hyun and Yoo Young realize that Suk Moo and Hwi Roo kept looking at each other during the trip.

Soo Kyung gets sick and gets taken to the ER. Ma Roo gets extremely worried about Soo Kyung, and she bursts out in rage as she hears what Soo Kyung’s mother says over the phone. Meanwhile, Yoo Young’s sister visits Yoo Young and triggers what she had been trying to deny while being with Jang Hyun.

Jang Hyun feels heartbroken as Yoo Young refuses to sign the marriage registration. Suk Moo gets called home by his father, so he tries to tell him that he and Hwi Roo are getting divorced. Meanwhile, Soo Kyung gets out of the hospital and starts to tell Ma Roo what she had gone through during her childhood.

Suk Moo gets worried as he keeps seeing Yoo Young jogging alone. Yoo Young goes out to a bar, but she just finds herself disgusted. Suk Moo finds Jang Hyun and tries to take him home, but he comes across Hwi Roo and Yoo Young on the way. The four of them end up sitting at a table and discussing about how they each feel.

Yoo Young and Hwi Roo come across each other while grocery shopping, and they start talking about Suk Moo’s habits. Suk Moo works for a night shift, but Jang Hyun suddenly calls him over. Meanwhile, a publisher company calls Hwi Roo and tells her that they are interested in her book.

Suk Moo takes Jang Hyun home and asks Yoo Young to let him take his clothes. Jang Hyun keeps wandering physically and mentally after hearing that Yoo Young doesn’t want him anymore. Meanwhile, Hwi Roo realizes that Suk Moo had much held inside himself for her sake and decides to be nicer to him.

Suk Moo keeps trying to find where Hwi Roo went. Hwi Roo continues to work on her storybook. Jang Hyun starts living at Suk Moo’s house, but he just can’t forget about Yoo Young. Meanwhile, Hwi Roo’s father visits Suk Moo’s house and asks Suk Moo where Yoo Young went.

After seeing his grandmother going out for curling, Suk Moo thinks he could finally find Hwi Roo and follows her to the curling center. Hwi Roo ends up meeting her father and admitting that she and Suk Moo got divorced. Meanwhile, Yoo Young finds Suk Moo wandering around and walks up to him.

Yoo Young suggests sleeping together with Suk Moo and goes to a motel with him. Suk Young pulls out a petition for divorce and gives it to Myung Geun. Hwi Roo gets extremely drunk and ends up kissing Jang Hyun. Meanwhile, Jang Hyun manages to tell this to Suk Moo while Hwi Roo apologizes to Yoo Young.

Hwi Roo is shocked to hear that Yoo Young tried to sleep with Suk Moo. Suk Moo tries to avoid Jang Hyun, but he keeps asking what happened between Suk Moo and Yoo Young. All four of them happen to come across each other all at once and end up having a heated conversation at Yoo Young’s house.

Yoo Young tells Suk Moo that she’s carrying Jang Hyun’s child. Hwi Roo finally gets her story printed into a book. Jang Hyun gets hospitalized after falling off from a rooftop. Suk Moo tries to keep his mind on his own life, but things seem to keep bothering him. While talking with Jang Hyun, Suk Moo realizes why he had been acting like that.