Summary: Nan-hee finds herself accepting a prize for winning the Spring Literary Contest but it turns out to be a dream as she wakes up from her sleep. In her real life, her mother constantly nags her to quit her job at a publishing company, which doesn’t pay her on time, and urges her to get married. Meanwhile, Nan-hee and Hyung-tae receive an identical text message simultaneously. Nan-hee calls up Hyung-tae after receiving the text message and realizes in mid-conversation that she and Hyung-tae had promised to spend the last day of their twenties together at Mt. Nam, and scheduled a text message to be sent to themselves a year ago to remind them. She tells Hyung-tae to keep his promise and heads to Mt. Nam. Amid other young couples, Nan-hee tries to get Hyung-tae into a romantic mood but it backfires. No sparks fly between them. And that is how they spend the last day of their twenties.

Summary: Hyung-tae returns home in a week after taking a sabbatical from work to see the world. He arrives at his home to see Nan-hee and Jung-joo together and the two men show their resentment for each other. Nanhee paid 6 months rent to stay at Hyung-tae’s apartment so she refuses to let Hyungtae live with her at the apartment. Hyung-tae convinces her that everything will be fine while they live together because he has no feelings for her... That is how Nan-hee and Hyung-tae become housemates. When Jung-joo hears that Nan-hee will live together with Hyung-tae, he causes a big commotion at the apartment. Nan-hee tries to calm down Jung-joo to little avail so she kisses him...

Summary: Nan-hee has a tough time after her break up with Jung-joo. Seeing Nan-hee so depressed, Hyung-tae forces Nan-hee into the bathroom and gives her a cold shower. He also rips up Nan-hee’s manuscript, which he then tries to piece together with Nan-hee in the shower. Meanwhile, Hyung-tae starts to develop feelings for Nan-hee after he sees her soaking wet in the bathtub and this surprises him. Nan-hee is upset at Hyung-tae but at the same time she is happy to have a friend helping her overcome the sadness of her breakup... Ahead of an important baseball game, Jung-joo discovers Nan-hee in the street and gets off the bus to meet her. When Nan-hee sees Jung-joo approaching, she takes hold of the steering wheel of a van and tries to get away from him...

Summary: Nan-hee and Hyung-tae each go home early after going out on dates with different people. They are surprised to see each other when they arrive home. Nan-hee asks Hyung-tae whether he is dating Ji-sun and when Hyung-tae mumbles something about how things are not working out in his relationship, Nan-hee is happy to hear that. Days later, Nan-hee spots her mother coming over for a visit and she immediately runs to her apartment to hide all of Hyung-tae belongings in a closet while Hyung-tae tries to find a place to hide...

Summary: While checking a message during a meeting, Hyung-tae looks down at a file that Ji-sun slipped to him and reads a note where she professes his love to him. After returning home, Hyung-tae sees Nan-hee napping at the table so he puts her down on the sofa where he sees her chest through her wet T-shirt and gets aroused... Meanwhile, Joo-young, a writer who writes a popular online story, apologizes to Nan-hee for hurting her pride and tells her she’d like to work at Nan-hee’s publishing company. Joo-young is also a fan of Jung-joo and writes a character in her book that resembles Jung-joo. She uses her book as an excuse to interview Jung-joo. While Hyung-tae stays late at work for days to prepare an important presentation, Nan-hee feels an emptiness around the home...

Summary: Nan-hee meets Jung-joo and her mother in front of her home at the same time. But before Nan-hee can do anything, Jung-joo jumps towards her and gives her a big hug. Flustered that her mother is watching her, Nan-hee lies to her mother and tells her she doesn’t know Jung-joo at all. But Jung-joo decides to rectify things and tells Nan-hee’s mother that he is Nan-hee’s boyfriend. Meanwhile, Nan-hee gets depressed over her mother’s disapproval of Jung-joo because of his age. Hyung-tae is approached by a neighbor who would like to set up an arranged date for him. He gets uncomfortable when the neighbor tells him she’d like to introduce Nan-hee to him but he finds it amusing at the same time and accepts the offer to meet her...

Summary: Jung-joo proposes marriage to Nan-hee so Nan-hee calls her friends for advice. But her friends Mi-gyeong and Sang-hoon who got married to each other in their early twenties, tell Nan-hee that dating and marriage are two different things. Her two friends end up getting into a big quarrel amongst themselves while dishing out advice. Hyung-tae starts to go out with Ji-sun and wears the ring that Ji-sun gave to him... Meanwhile, Hyung-tae and Ji-sun can’t enter their apartment because Nan-hee’s mother is waiting in front of the place. So they wait until Nan-hee arrives. When Nan-hee finally comes home, Hyung-tae takes her to the parking lot for a talk and they bump into Jung-joo and Joo-young who were coming to see Nan-hee. Nan-hee gets her mother to go home but while she is on her way, she heads straight towards Soon-ok, a friend of hers and a neighbor of Hyung-tae and Nan-hee. Nan-hee and Hyung-tae try to prevent Nan-hee’s mother from seeing her friend and things get hairy ...

Summary: When Ji-sun inquires about Hyung-tae’s plans to go fishing with his father and Nan-hee, Hyung-tae brushes off her concerns by telling her that he’s just friends with Nan-hee. Nan-hee accepts Jung-joo’s marriage proposal but she gets depressed over it. Hyung-tae tries to cheer up Nan-hee and tells her that she could do better and advises her not to marry Jung-joo... Meanwhile, Jung-joo tells his coach that he will forgo college and turn pro to play in the minor leagues. Jung-joo borrows Hyung-tae’s suit to meet Nan-hee’s mother and gain her approval but Nan-hee’s mother is adamant and won’t approve of him as her future son-in-law. But Jung-joo is resolute about his commitment to Nan-hee and says that he will be a faithful and loving husband to Nan-hee, who gets very impressed. Then they kiss...

Summary: Nan-hee goes to Jung-joo’s training camp and asks him to sign his autograph on a baseball. She tells Jung-joo that she’ll never sell the ball even it if becomes an expensive baseball souvenir later on and then she breaks up with him. Hyung-tae comforts Nan-hee after she breaks up with her boyfriend and tells her he’ll marry her if she is still single at the age of 40. Meanwhile, on the day Nan-hee will go on a blind date, Ji-sun offers to fix her makeup for her. When Ji-sun tells her that Hyung-tae confessed his love for her, Nan-hee feels sad and it surprises her that she feels that way.

Summary: Nan-hee looks at the free trip tickets that Jung-joo won and since it is in her hands now, she decides to go on a trip by herself. Hyung-tae finds out about the tickets Nan-hee has and since it is a trip for two, he convinces Nan-hee to let him go with her. On the trip, Hyung-tae confesses his love to Nan-hee at the beach resort. Nan-hee doesn’t take Hyung-tae’s confession seriously at first but then she realizes that Hyung-tae truly means what he said...

Summary: After his vacation is over, Hyung-tae returns to work to discover that his scandalous relationship with Ji-sun is a hot conversational topic around the company. When Ji-sun acts like she’s Hyung-tae’s lover to seemingly prove that the rumors are true about their relationship, Hyung-tae politely tells Ji-sun he thought they were no longer a couple. Meanwhile, Nan-hee tries to avoid bumping in Hyung-tae as much as possible after her friendship with him takes a new turn. Hyung-tae gets irritated when he sees Nan-hee deliberately avoiding him so he tells her she can drop the act because he no longer has deep feelings for her...

Summary: While on his way to meet some friends, Hyung-tae is stunned to get a call from Sung-ah. Sung-ah looks at Hyung-tae’s reaction from afar and then she approaches him to say hi. When Hyung-tae and Sung-ah arrive together at the gathering, Nan-hee Chun-hee, Mi-gyeong, and Sang-hoon are shocked to see them together. Hyung-tae acts like his normal self around Sung-ah. Meanwhile, Nan-hee and Hyung-tae both decide to become friends again and they agree to stop getting too involved with each other. Hyung-tae goes to Sung-ah at her studio since he is in charge of promoting her new album...

Summary: Hyung-tae tells Nan-hee that he is disappointed in her because she’s been quietly looking for a place to rent. He pleads with her to stay until she submits her entry to the Spring Essay Contest. Nan-hee gets teary-eyed and tells him she wants to leave the apartment before her feelings for him become too deep. She says their friendship has reached its limits. Meanwhile, on the day of the book signing event for Ju-young, who is an author signed with Nan-hee’s publishing company, Sung-ah, Nan-hee, Hyung-tae and some friends decide to go to the bookstore to get their books signed by her. When Ju-young is signing a book for Hyung-tae, she blurts out that Nan-hee’s roommate is here...

Summary: Sung-ah accuses Nan-hee of being in a closer relationship with Hyung-tae than she says she is and Nan-hee gets annoyed that she has to explain to Sung-ah that she’s just a friend. Sung-ah tells Nan-hee she would feel more confident about her chances of winning Hyung-tae back if Nan-hee decides to seduce Hyung-tae with her looks. But if Nan-hee were to remain as Hyung-tae’s friend, Sung-ah believes her chances would plummet. Sung-ah’s remark deals a blow to Nan-hee’s pride so she bites Sung-ah’s arm. Later in the day, Nan-hee has a drink with Hyung-tae to celebrate the deadline for her entry to the Spring Essay Contest. As they talk about the same old stuff over and over, Nan-hee and Hyung-tae try to give each other dating advice like they used to but it only dampens the mood...

Summary: By coincidence, Nan-hee and Hyung-tae bump into each other at an outdoor bar. They sit together and have a light conversation at first. Both of them missed each other deeply but they don’t say it right away... Hyung-tae confesses that he missed Nan-hee and tells her that he wants to be more than just friends. Meanwhile, Sung-ah is at Hyung-tae’s apartment where she is changing the bed covers and getting rid of any stuff that belonged to Nan-hee. On the day Nan-hee holds a housewarming party, her friend Chun-hee asks Nan-hee what her definition of love is. Nan-hee says that love is all about good timing. Hyung-tae avoids the question by saying nothing.

Summary: Hyung-tae works hard to prepare Sung-ah’s first domestic concert. Ju-young gives Nan-hee a few tips on how to become a better writer and suggests that they work together again when she published her next book.