On a rainy day, Lee Min Kyung and Noh Hwi Oh experience a series of increasingly unpleasant encounters, unaware they live next door to each other.

At the police station, Min Kyung and Hwi Oh go at each other's throats. Later, Hwi Oh is advised to stay away from people who trigger his anger.

Bumping into an old coworker dredges up painful memories for Min Kyung. With a flasher on the loose, Hwi Oh is roped into patrolling the neighborhood.

Min-kyung is determined to find her missing dog. Getting wind of drug dealing activity on a chatting app, Hwi-oh sets out on an undercover mission.

The flasher resurfaces, this time in front of Min-kyung, but thankfully Hwi-oh is close by. The next day, she asks him for a favor.

Hwi-oh trains Min-kyung in the basics of self-defense. But soon, Min-kyung's anxiety returns in full force with the arrival of a sudden piece of mail.

A sudden incident in the night scares Min-kyung, who feels vulnerable living alone. Hwi-oh's mother discovers a woman in her son's apartment.

Min-kyung exchanges harsh words with her mother. She's further shaken by the identity of a prospective tenant who comes by to see her apartment.

Malicious rumors about Min-kyung spread online. While other neighbors turn against her, Hwi-oh promises she can always count on him to take her side.

As a show of repentance, the Women's Association sets out to help Min-kyung. After a night of drinking, Min-kyung tells Hwi-oh she wishes to see him.

After receiving good news at the psychiatrist's office, Hwi-oh heads to the police station. At the apartment, Min-kyung panics when her dog gets loose.

Hwi-oh's fury takes over when Min-kyung's ex-boyfriend shows up at the apartment. Lee Su-hyeon finds out that a video of her singing has gone viral.

Resolving to protect Hwi-oh, Min-kyung meets the one person she wanted to avoid. Concerned for her safety, Hwi-oh chases after her.