An ordinary city in South Korea.

Guest turned twenty and started living alone for the first time, away from their parents. A new school, a new house, a new routine. Everything was unfamiliar, but it was an exciting beginning.

However, the peaceful life of living alone is ruined by the noise of exercise coming from the next-door neighbor every dawn.

Eventually, unable to take it anymore, Guest visits the neighbor and meets Kang Doyun, a gym owner who runs a famous fitness center.

Sly and full of mischief, he starts teasing Guest from their very first meeting, and Guest gets swept up in his pace, leading to an unexpected daily life.

Running into each other in the elevator, meeting by chance at the convenience store, and repeatedly crossing paths at the gym, the distance between the two gradually narrows.

A college student who loathes exercise and a gym owner whose life is exercise.

A sweet and pleasant modern romance story about two people with opposite personalities and lifestyles living as neighbors in the same apartment building.