Yumi's Cells

After breaking up with Woong, Yumi and her cells are struggling to keep her life together. Although she acts as if nothing happened, Yu-mi is suffering from post-breakup syndrome and Ba-bi comforts her. In no time, a Yoo Ba-bi club has formed in the cell village without Yu-mi realizing...

Although Yu-mi was taken aback by Ba-bi's sudden confession, her confidence level shoots up. Yu-mi becomes more preoccupied by Ba-bi and she unconsciously finds herself getting heated up when Ruby sets up a date for Ba-bi.

News of Ba-bi's date puts Yu-mi in despair. Yu-mi wishes he doesn't go on the date. But she couldn't tell him in the end... On the day of Ba-bi's date, Yu-mi falls asleep after feeling perturbed the entire day, when a message from Ba-bi arrives.

Yu-mi's sweet romance with Ba-bi begins... Her new romance leads her onto a new path. When Yu-mi goes to a book cafe with Ba-bi, she is reminded of her long-lost dream. Although she knows it's too late, someone keeps encouraging Yu-mi to pursue her dream.

Yu-mi and Woong meet again during second-hand market meet up. Unlike Woong who thought it was a fateful meeting, Yu-mi is confused by what Woong said in the past as compared to his current situation. While Yu-mi is trying to enjoy her Christmas with Ba-bi, a message from Woong arrives.

Yu-mi works hard from day-to-day as an aspiring writer. Ba-bi visits her house to cheer her on. While the two of them are enjoying their date, an unexpected visit from Yu-mi's parents catches them by surprise... Yu-mi's father begins to openly keep Ba-bi in check.

Unlike her courageous start, Yu-mi continues to taste failure from all her contests. Despite Writer Cell's efforts to keep her mind together by recalling wise sayings, Yu-mi feels dejected at her own lack of talent... At that moment, she receives an offer from Mr. Nam to reinstate her position at Daehan Noodles.

Da-eun, an intern at Daehan Noodles' Jeju branch, likes Ba-bi but she decides to give up when she realizes Ba-bi has Yu-mi. Meanwhile, the chief editor at Julie Literature, Ahn Dae-yong, finds out that Yumi, the writer he picked, is his first love from his college days and believes that this is fate...

Yu-mi starts working with the oddball illustrator Control Z. Although she's on the verge of exploding when Control Z nitpicks at everything, she controls herself to stay professional. When Yu-mi flies to Jeju to spend the new year with Ba-bi, she finds out that Ba-bi is giving up his lease.

After the breakup with Ba-bi, Yu-mi's writing improves greatly thanks to Writer Cell who has become the Prime cell. Now a successful entrepreneur, Woong is surprised to find that Yu-mi is now a writer. When he meets Control Z through a business meeting and learns that he is the illustrator for Yu-mi's works, his heart pounds restlessly...

When Yu-mi hears that Ba-bi has returned to Seoul, she notes down the places that Ba-bi frequently visits to avoid him but ends up running into him at his go-to cafe. Having thought over countless times what he would say to Yu-mi if he meets her again, Ba-bi holds her back...

As the war of nerves between Woong and Ba-bi rages on, Yu-mi is put in a tight spot by the unexpected three-way encounter... Meanwhile, Yu-mi finds out that Ba-bi is going to America for a business trip while planning for his birthday. With everything happening at bad timing, will getting back together with her ex be that hard?

After being proposed to by Ba-bi, Yu-mi goes to meet Ba-bi's father. Yu-mi tries her best to make a good impression on Ba-bi's father, going as far as to summon her full-of-manners self. Meanwhile, Woong hears of Yu-mi's wedding and asks to meet her...

On the day of the wedding, Yu-mi is unable to meet the deadline. She falls into a panic when she loses her laptop containing the manuscript. At the wedding, all she can think of is running away from reality... At that moment, someone contacts Yu-mi and says that he found her laptop. Who could it be?