Sound director Park Do-kyeong starts to see hallucinations of a woman he doesn't know. Turns out to be Oh Hae-young, who dumps his boyfriend on their wedding day.

After her wedding is cancelled, her parents are on the verge of making her leave the house. She finds a small room to stay in, only to find Do-kyeong living right next door.

Hae-young and Do-kyeong don't get along well living with just a thin wall between them.

Hae-young and Do-kyeong grow fond of each other and one day even have breakfast together.

Hae-young's mother senses a fling between Hae-young and Do-kyeong, while Hae-young's birthday is just around the corner.