Because This Is My First Life

Woo Su-ji, a school friend of Ji-ho who works in a corporate office. Her dream was to be the CEO of her own business but she is trapped in a well-paying position where she must bear with frequent sexual harassment from her male colleagues.

Lee Eun-sol, Ji-suk's pregnant wife.

Kim Hyun-ja, Ji-ho's mother who is a full-time housewife.

Yoon Ji-suk, Ji-ho's younger brother.

Nam Se-hee, a quirky and apathetic computer designer who has bought an expensive townhouse and rents out his extra room to help with the mortgage. He spends his days at work or home with his cat and has no plans to date or marry. After a series of bad tenants, he rates Ji-ho very highly and, believing she is a male, he offers her the room.

Yeon Bok-nam, a colleague of Ji-ho's.

(Episode 1)

(Episode 1)

Yang Ho-rang, a school friend of Ji-ho who is a hostess at a restaurant/bar and dreams of becoming a wife and mother.

Writer Hwang.

Nam Hee-bong, Se-hee's father who is a former high school principal.

Sim Won-seok, Ho-rang's long-time boyfriend who is the CEO of a startup company which is having problems getting an investor.

Yoon Ji-ho, an assistant screenwriter who moves out of the home she shares with her brother when he marries his pregnant girlfriend. Currently between projects, she rents the room from Se-hee (who Ji-ho thinks is female) because the rent is affordable and no deposit is required. After working hard at her career throughout her twenties, at age 30 she has never dated and has a career crisis that causes her to rethink her goals.

Go Jung-min, Se-hee's ex-girlfriend, a successful businesswoman.