Episode 6 of Our Universe begins with Tae-hyung pouring his heart out to Hyun-jin, confessing that she's the first person who's always been there for him and the one who waits for him to return home. At that tender moment, their neighbor interrupts with a basket of food, providing Hyun-jin with a much-needed distraction.
The following morning, Hyun-jin finds herself awkwardly avoiding Tae-hyung's gaze and rushes out of the house. She receives a call from Saetbyeol Daycare informing her that a spot has opened up for Woo-joo. She quickly messages Tae-hyung, asking him to drop Woo-joo off at the daycare. He complies and even gets emotional as he leaves the boy behind. While sending Hyun-jin an update, he accidentally sends her a selfie and panics. Se-yeon, noticing Hyun-jin's reaction, asks what's going on with Tae-hyung. Hyun-jin confides in her, and Se-yeon points out that she now has two men who clearly care about her - Tae-hyung and Yoon-seong. But Hyun-jin is focused on Woo-joo and her career.
After work, Yoon-seong invites Hyun-jin to a cafe. He seems relieved to hear that Tae-hyung will be moving out soon, as his month-long arrangement with her is coming to an end. Meanwhile, Jo Moo-saeng gives Tae-hyung all his new duties as Amy Choo's assistant. On set, Tae-hyung impresses Moo-saeng with his work.
Back home, the air between them remains awkward. Tae-hyung receives a call informing him that his apartment has been repaired. He's surprised to realize that a month has already passed. He tells Hyun-jin that he meant what he said but won't push her. They decide to let things continue as they were.
That night, a suspicious man in a black hat approaches their apartment but leaves when he hears Woo-joo crying inside. The next day, Tae-hyung's neighbors tell him that a suspicious man in a cap has been spotted around the building. Apparently, he's known for targeting single women, and several apartments have been robbed. Tae-hyung messages Hyun-jin and asks her to come home early for a few days.
Tae-hyung steps into his pristine new apartment, its gleaming surfaces and pristine state an almost-too-perfect backdrop for his reluctance to settle in. Despite the perfection, he searches for flaws, delaying his move-in day. That evening, Hyun-jin falls asleep on the bus, missing her stop. On her walk home, she senses a man tailing her, and her instincts kick in, sending her into a sprint. Colliding with Tae-hyung, who had emerged to search for her, the man vanishes. Tae-hyung urges Hyun-jin to reach out if she feels threatened again and lies about his apartment, claiming it’s not ready for occupancy. He even hands her a pepper spray but accidentally sprays it in his eyes, prompting Hyun-jin to help cleanse them. In the process, she slips on the bathroom floor, and Tae-hyung catches her just before she falls.
The next day at work, Yoon-seong successfully negotiates a deal with Amy Choo and her team for the visual campaign with GloMarket. Hyun-jin is surprised to see Tae-hyung arrive with Amy Choo. The meeting progresses smoothly until someone suggests dinner together. On the way, it's revealed that Tae-hyung and Hyun-jin are the couple from the viral lobby video. They explain their situation, with Hyun-jin firmly stating they're not dating.
During dinner, Tae-hyung and Yoon-seong compete against each other, resulting in a bowling match. Tae-hyung emerges victorious and impulsively hugs Hyun-jin. After the match, Moo-saeng reminds Tae-hyung they need to return to the studio, leaving Yoon-seong to escort Hyun-jin home. They stop by the river to watch fireworks. A flashback reveals that Yoon-seong had invited Hyun-jin to see the fireworks years ago, but she lied about leaving for a language program because she found out he gave up a scholarship for her. Now, she admits realizing he knew about her financial situation and lied to protect her pride. In truth, Yoon-seong had known all along and understood her reasons.
Yoon-seong drops Hyun-jin off at home and waits for her to enter. As she approaches the front door, Tae-hyung calls her on the phone. As she talks to him, she notices the door is open and someone is inside!
