She rushes to the hospital, and soon, the family welcomes their newest member. Dad wipes away a few tears, and behind them, Ji-seok audibly sobs on the floor. Mom and Ji-ho coo over the newborn baby, agreeing that this is the greatest gift in life, and Ji-ho suddenly drops the truth to Mom: And besides, she already knows that the decision must have been difficult for Ji-ho, as will be the consequences afterwards.
Mom smiles, surprised that she still remembers such an old memory, and tells her that both sets of parents disapproved of their marriage. But the day Mom decided to get a divorce, she looked at Dad sleeping and realized that if she broke up with him when they were dating, she would have missed him all her life.
Once she realized that, she decided it is was best to just live with him. She says she wants to fill her star pocket with sparkly things, and smiles up at her mother. She yells at Ji-ho to keep her divorce a secret from her dad for now, and curses her under her breath as she walks away. Marriage is something that sparkles. Marriage is something that makes you take another look back even if you hate the other. We took marriage too lightly. For the first time, I felt ashamed. We revisit their goodbye scene at the door, where she suggests a parting handshake.
They wish each other the best of luck since this is both their first divorce, and Ji-ho thinks that since their relationship started with a handshake, it was only right to end it with one, too. Before separating, Sang-gu invites Park to smoke together, but when Park offers him a cigarette, Sang-gu explains that he quit. A familiar-looking motorcycle rides up to them, and Sang-gu introduces his new girlfriend.
The motorcyclist takes off her helmet and flips her hair in slow motion, revealing Su-ji. She greets Park by his first name, and Sang-gu puts on the spare pink helmet as he takes his seat behind her. They make some jabs at Park and wave goodbye, leaving him completely stunned. Sang-gu accompanies Su-ji while she buys bras for research, and as he bids her farewell at her apartment, she invites him in for ramyun.
Meanwhile, Se-hee puts his own place up for sale and receives potential buyers. Once they leave, Se-hee looks around and imagines Ji-ho eating here, watching soccer, and doing her usual things. He peeks into her empty room, remembering her sleeping there, and notices a letter on the bed, which the prospective buyer had found dropped on the floor.
In it, she asks if he watched soccer and if Cat is well, wondering how long it would take for him to find this. She admits to entering his room once and finding the poetry book, and to knowing about Jung-min, and apologizes to Se-hee.
Ji-ho adds an interesting story about Mongolians, who carry their dead to a remote place rather than bury or cremate them. Later, when they return to the place to check the bodies, they mourn if the body is still there but rejoice if only bones remain. She wonders what will be left in her heart on her way back after she leaves this room. Won-seok asks where Ji-ho went, and Se-hee guesses Mongolia. In reality, Ji-ho is reading comics with Ho-rang at the sauna, living at a guesthouse housing mostly foreigners in Seoul.
Ho-rang offers her the rooftop room for Ji-ho to use since Won-seok moved out and their lease is still valid, and Ji-ho happily accepts.
Su-ji makes a pot of ramyun for Sang-gu, but as he grabs some, he struggles to eat the clump of still-hard noodles. Apparently Se-hee plans to use all of his vacation days at once, and Sang-gu complains about how much the company is suffering as a result. Se-hee mopes on the couch while watching soccer, and dryly comments on his team scoring again. With her limited English, Ji-ho tries to convey her feelings, but ultimately decides to explain it in Korean: Afterward, Won-seok and Sang-gu worry that that the rooftop apartment would be too small.
Se-hee says that he just needs a place to sleep and eat, and his sudden change in philosophy makes Sang-gu nervous. Bo-mi finds Won-seok and asks him to play the recording of his game earlier. She analyzes his strategy, explaining why he lost, and Won-seok praises her analysis. She tells him that games, formulas, and game formulas are her favorite things much like Won-seok , and asks him if he wants to date.
Se-hee brings Woori to their new place, while at his old place, Ji-ho gapes at the stranger who answers the door. She tries calling him, but to no avail since he left his phone behind while buying more beer, and they both walk to the same place a small distance apart. When Ji-ho arrives, she sits outside with her cake, sighing over her missed chance to propose to him about starting again.
Ji-ho remembers the moments she shared with Se-hee, both the good and the bad, and thinks to herself that she wanted to leave that room and see what was left in her heart. Looking back, she realizes that neither hatred nor pain was left—instead, there was just longing.
With dawning realization, Ji-ho slowly turns around and enters the apartment, where she finds Se-hee sleeping with the snail doll on the bed. She lies down next to him, and Se-hee drowsily opens his eyes. In the morning, Se-hee wakes to a cleaned room and a thermos filled with tea, and jokingly asks Woori if she made it. Cracking another beer, he steps outside, and as he takes a swig, he stares wide-eyed at Ji-ho standing in front of him.
Inside, she merrily eats crab, and Se-hee asks how she can eat in this situation. Eventually Se-hee blows up, yelling at Ji-ho for not contacting him even once when she was so close, saying that he missed her and had a hard time.
Ji-ho apologizes for leaving him when he was having a hard time, and opens up her arms, offering him a hug. Se-hee rejects her offer, sulking on the bed, and Ji-ho continues to playfully pester him while he childishly pushes her away. He pushes her onto the bed, and reminds her that he told her to stop.
Won-seok looks at the data Bo-mi gave him about their match rate, which is over 90 percent, and meets her to give her his decision.
Using an analogy, he calls Bo-mi a Mac OS, and though he finds her new, interesting, and intuitive, he still misses Windows. Bo-mi simply smirks before walking away. Ji-ho and Se-hee cuddle in bed together, and she tries to wake him for dinner though he protests for more sleep.
Se-hee offers to make omurice for her, but Ji-ho bluntly tells him to just order chicken. Therefore, instead of giving up anything, she frames her actions as choosing something, which was love. He says that he never wants to be apart again, and wants to be her legal guardian so he can rush to her side first when she needs him. They cheer to that, but then Ji-ho asks sharply if he met with Jung-min alone. Se-hee offers to change his number, but Ji-ho tells him to forget it while shooting daggers at him.
After hanging up, Ji-ho gets a message from Jung-min, who congratulates her about her lawsuit. She also tells Ji-ho that a different production company will contact her since she promoted her work purely as a fan. He ends the call with a kiss, and everyone reels back in horror. He asks if she can tell him the reason, and she takes out the ring Won-seok gave her.
Without any resentment, Young-hyo accepts her decision and agrees with her statement, and the two high-five, signaling their end. Won-seok hesitates over calling Ho-rang, and asks Se-hee if Ho-rang ever comes by the apartment.
Won-seok rushes out of the office to stop Ho-rang, and Se-hee gives himself a congratulatory fist pump. Won-seok spots Ho-rang getting into a car, and chases after futilely. Ho-rang arrives at the district office, and bids one last farewell to Young-hyo as they both wish the other luck in marrying someone they love. Won-seok argues that they should cherish it all the more and asks for one more chance.
Relocating to a coffee shop, Ho-rang assures Won-seok that she could never accept a different ring, and tells him that the one he gave her is enough for this life. Ho-rang proposes first this time, asking Won-seok to marry her.
Ji-ho narrates that Gary Becker once said that people get married when it provides more benefits than living alone. He picks her up and surprises her by saying he booked the same flight to accompany her on her business trip. As they get out of the car, Su-ji suggests sharing mileage points so Sang-gu can upgrade his seats, but he points out that those can only be shared with family members. Su-ji simply says that they should get married then, but Sang-gu harrumphs over her seemingly trivial reason.
She huffily tells him that she saved for years for those points, and takes back her proposal, grumbling that she even brought their son today. Sang-gu looks at the backseat to see a new doll buckled in next to their old one.
With a smile plastered on his face, Sang-gu chases after Su-ji and happily announces his intentions to stick with her forever. He also said that marriage is the beginning of a relationship. Some time later, as Ji-ho writes her script, Se-hee feeds her a red ginseng packet—the exact same PPL Ji-ho wrote into scripts when she was an assistant writer.
Taking a break, Ji-ho sits in a massage chair, and Se-hee asks if she wants a beer while tousling her hair. Through her narration, Ji-ho explains that they registered their marriage three years ago, and rewrote their contract.
They agree to both pay half the lease and jointly own the apartment. They also agree to visit their families separately on holidays since their feelings come first and trump any cultural norms.
While they revise their contract every year, the most important condition never changes: Love is their top priority. Out in the street, our three couples chase after the bus, and sit all together in the back row.