The fourth episode starts with Seok-ryu and Seong-hyo, where Seok-ryu puts on Seong-hyo’s clothes that he always has on hand for work trips. He makes fun of her height and they argue. It is now the moment for them to open the time capsule and read their personal letters, but Mo-eun’s letter is nowhere to be found. Upon finishing his, Seong-hyo dashes home directly to prevent Seok-ryu from snatching it away from him. Afterwards, he is weighed down by the letter and attempts to persuade himself that he no longer harbors feelings for Seok-ryu and has outgrown his high school crush.
The following day, we discover that Seok-ryu’s family is facing financial difficulties, and her parents are in a dispute over the condolence money her father intends to offer to a friend. In the meantime, Seong yu’s parents appear to be in a state of great distress with each other, with his mother feeling that her husband is eager for her to depart for her diplomatic assignment.
Afterwards, with nothing to do, Seok-ryu loiters at Seong-hyo’s office when Myung-u tells them that Greip, Seok-ryu’s previous company, is interested in collaborating with him. Myung-u’s contact in America suggested their company. The difficulty lies in the fact that both of them lack sufficient English skills to communicate effectively, so despite Seok-ryu feeling uneasy, she takes on the role of their translator. Afterwards, Seong hyu inquires why she assisted him and she confesses it’s because of him. When she attempts to persuade him to leave the office and have a meal, he remains stubborn despite getting slightly agitated, stating that he enjoys his work so much that he is willing to go without food for seventy two hours in order to focus on his work.
At the same time, Seung hyo’s mother is feeling uneasy because she has not been taken anywhere. She encounters Seok ryu’s mother while driving and gives her a ride. Seok Ryu’s mother suggests that she should prioritize spending time with her husband, while Seung Hyo’s mother attempts to conceal her doubts about her marriage.
In the meantime, Seung hyo’s father visits Seok ryu’s father’s eatery and dines because his wife didn’t cook at home. Both men are having a conversation. Seok ryu’s father laments about how his wife disrespects him due to his lack of wealth. He is jealous of the other for having it all, while the latter envies him for his simple lifestyle.
In another place, Mo-eun and Dan-ho cross paths at the convenience store and appear to have become competitors due to their similar preference for uncommon flavors and items. Afterwards, Seok-ryu and Seong-hyo also bump into the two, and they engage in conversation. Dan ho remains saddened by the fact that Mo eum ultimately got the drink. Yet, he recognizes Seok ryu and when she attributes it to her looks, Seong hyu warns her against saying it in public. Dan-ho finds out that the trio were childhood pals, yet he responds vaguely when Mo-eun inquires about his previous residence and abruptly departs from the gathering to return home.
Nevertheless, while heading back home, Mo eum states that she believes he is suspicious. Then, she discloses that she took out her own letter from the time capsule. She clearly read Seong hyu’s letter but remains silent. While he is experiencing panic. He pretends to make a phone call and quickly leaves.
The next day the virtual gathering with Greip concludes, Seong hyu observes the camaraderie between Seok ryu and Myung u, discovering that they even follow each other on instagram. Seok-ryu eavesdrops on the Greip team talking about choosing another company because Seong-hyo’s company is new and lacks a proven track record, while the two men step out to take a call. She informs Seung-hyo, but he remains adamant about giving his best effort and requests that she does not disclose this to Myung-u. She is mad at him for continuing to give his all for a company that belittles individuals. She is aware that his efforts will be futile, but Seung hyu points out to her that she is not familiar with him.
At the same time, Dan-ho assists Mo-eun’s mother, who is a real estate owner that had previously aided him in securing his apartment, by carrying some boxes. Seok-ryu’s mother comes in, is impressed by him, and asks about him for Seok-ryu’s possible partner. Nevertheless, Mo-eun’s mother refrains from disclosing a crucial detail about Dan-ho because of an interruption.
In another location, Mo-eun encounters a fascinating 6-year-old girl searching for crop circles at the park. The girl appears to have a belief in extraterrestrial beings and a passion for science fiction, similar to Mo-eun during her youth, which instantly endears her to Mo-eun.
At the same time, Bae Dong jin, Seok ryu’s sibling, encounters Na yun at a fitness center where he works out and tries to flirt with her. However, since she is infatuated with Seong yu, she pays little attention to him.
Later that evening, Mo eum informs Seok-ryu that she encountered a child and gets upset for not inquiring about the child’s name. She suggests Seung hyo join them for a walk later, but Seok ryu refuses and Mo eum suspects they quarreled.
The following day, Mo eum and Dan ho run into each other at the convenience store, but now they are competing against each other for a lollipop. It’s absurd since it appears there are a greater number of lollipops with that flavor available in the store. Following their separation, Dan ho goes back to his flat to unpack. He sifts through previous videos of Seong hyu swimming when he suddenly stumbles upon a photo of him and Seok ryu from their high school days. He shares the photo with Seong hyu, who is taken aback. He believes Seok ryu won’t show up because of their disagreement, but she still manages to come.
Seong-hyo, Myung-u, and Seok-ryu eventually arrive at the important gathering, where Seung-hyo will introduce their proposal to the Greip delegates. Alone, he questions Seok ryu about her reason for being there and she replies that she came to assist him with English interpretation to prevent his subjugation.
Seok-ryu is uneasy when she comes across a former colleague who has become a team leader. During a flashback scene, it is shown that Seok-ryu experienced workplace bullying from her colleagues, who coerced her into completing all of their tasks. There is a gossip circulating regarding the career pause she had taken a couple of years back.
Overwhelmed by the team member’s presence, Seok-ryu excuses herself to the bathroom. While returning, she encounters the team member who belittles her and mocks her. Seung-hyo hears how he bullied Seok-ryu and then punches him. In the face of danger, Seok-ryu embraces her intense “crazy woman” alter ego and overpowers Greip, warning him with proof of his wrongdoing at the company. She goes away to refresh her mind and Seong hyu trails behind her. They ultimately take a seat and have a conversation. Seok Ryu shares her experience of being harassed while working at Greip. Nevertheless, she thinks she didn’t stay in the job because she didn’t enjoy it unlike Seong hyu. Afterwards, Seong yu brings her to the Namsan tower to place love locks and cast spells on her enemies.
She suddenly informs him that she was amazed by him and Seong yu teasingly cautions her not to develop feelings for him.
While at the location, Myung-u lets them know that Greip has offered them a new job because they enjoyed their designs. He also discloses that Seok-ryu’s ex-colleague has been terminated. Myung-u happened to secretly record their chat and is also buddies with the vice president of Greip! Seok ryu is extremely thrilled and ends up hugging Seong hyu tightly, leaving him feeling flustered.
During a flashback, it is revealed that Seok-ryu missed a crucial practice test in order to back Seung-hyo during his competition. Dan-ho took a photo of them, which he then forwarded to Seok-ryu in the current moment. During another moment from the past, Seung-hyo pays a visit to Seok-ryu in the United States and brings her numerous items from Korea. When he presents her with her favorite books, she embraces him. She stumbles into his chest while intoxicated and falls asleep.