The season’s last episode begins with our adorable housemates preparing to go on a road trip. Tae-oh rents a car and Do-hyun and Song-yi try to sit beside each other. We flash back to a few days ago when Song-yi was on the phone with Do-hyun, making plans for their trip. She’d left her laptop open on an article about restaurants in Gangneung which Tae-oh had seen and been dismayed that she was going on a trip with her boyfriend so soon.
Hoon perfects his choreography at the rehearsals but a fellow actor discloses that he was asked to be the understudy and Hoon might get fired. Tae-oh grills Song-yi about the trip with her boyfriend, lecturing her about her boyfriend looking for excuses to ‘spend the night’ but Song-yi only appears excited about the prospect. Hoon bursts through the gates looking devastated and proceeds to drink heavily. He tells his housemates that he got hired as an understudy with no role and no lines and might even get fired from that job. He walks away grumbling that he would like to go far away, which gives Tae-oh the idea for an impromptu road trip to Gangneung with the entire group.
Do-hyun is disappointed at this turn of events, complaining that he just wanted it to be the two of them. He asks if it’s possible to tell the others that the trip is cancelled but Song-yi tells him that Hoon and Ga-rin have already begun packing for the trip. Back in the present, the group goes to pick Se-hyeon up and finally set out on the road trip.
During the journey, everyone takes selfies while Do-hyun clandestinely holds Song-yi’s hand. They stop at a beach and Se-hyeon takes pictures. She happens to overhear Hoon and Ga-rin talking about grabbing chargers from Tae-oh’s room, which strikes her as odd. Tae-oh teases Song-yi, saying she must be having more fun with a group and how her boyfriend had other intentions. But she fires back saying her boyfriend should be having those intentions and asks if Tae-oh plans to have a platonic relationship with Se-hyeon forever.
As they all try different fun activities, Tae-oh notices how close Do-hyun and Song-yi are to each other. When Tae-oh and Do-hyun split from the group, Tae-oh complains to him that Song-yi was planning to come with her boyfriend. He also reveals that he asked Song-yi to break up with the guy, leaving Do-hyun exasperated. Song-yi spots a group of boys checking Se-hyeon out and wonders if Tae-oh finds her that pretty as well. Se-hyeon inquires about Song-yi and Tae-oh’s friendship as well as his family. Do-hyun asks why Tae-oh wants Song-yi to break up with her boyfriend and Tae-oh recounts the night she got back home alone completely drenched. Do-hyun then realizes that Song-yi lied to him. When Tae-oh says he can’t let that guy have Song-yi, Do-hyun tersely points out that she’s not an object he can make decisions for.
Ga-rin is so happy to be on a trip with her friends that she can’t stop skipping. She confesses to Hoon that when she left home she was anxious about her path in life, but not anymore. She tells him that she’s confident things will turn out well for him too and gets him to do breathing exercises with her. The group make their way to the vacation house that Tae-oh has rented. Do-hyun overhears Tae-oh teasing Song-yi about the platonic love comment she made, leaving her hilariously embarrassed.
Se-hyeon overhears Hoon saying that he’s sleeping on a bed after a long time. Song-yi sees a text from a certain ‘Seong-jin Oppa’ on Se-hyeon’s phone but hides it when she sees Tae-oh approaching and asks her to accompany him for grocery shopping. Do-hyun looks all over the villa for Song-yi until receiving a text about her whereabouts. She catches him shopping for cotton bed sheets for Se-hyeon and wonders why she has to be so oversensitive. On their way home, the two make a wrong turn and end up spending some time on the beach.
Do-hyun seems bothered by how long Tae-oh and Song-yi are taking while Se-hyeon tries to find out where Ga-rin is living. Song-yi tells Tae-oh not to trust Se-hyeon too much but he assumes she’s being jealous. When they return, Do-hyun is cold to Song-yi and Se-hyeon inquires about Tae-oh’s company while he’s gone. At dinner, Hoon gets a call informing him of his contract termination which puts a dampener on the night.
Song-yi texts Do-hyun to meet her by the pool while Tae-oh tries to cheer Hoon up. Left alone with Se-hyeon, Ga-rin lets it slip that Hoon and her live together and Se-hyeon figures out that Hoon, Garin and Song-yi are living with Tae-oh. Do-hyun admits to Song-yi that her friendship with Tae-oh bothers him and makes him react in ways he doesn’t know how to handle. She sweetly points out that while her history with Tae-oh can’t be helped, Do-hyun is a part of her dating history. This pleases him and he kisses her. Tae-oh sees them kissing and wonders what the uncomfortable feeling he’s having means.