Radio Romance

Woo Ji-woo, Soo-ho's friend who liked Geu-rim 12 years ago but died in a car accident.

Go Hoon-jung, a 30-year-old radio assistant director.

"Tornado"

Nam Joo-ha, Soo-ho's 51-year-old biological mother who serves as CEO of JH Entertainment.

Ji Soo-ho, a top actor who is accustomed to act based on scripts. He ends up becoming the DJ for a live radio show where nothing ever goes according to plan. Nam Da-reum as young Ji Soo-ho

Young Song Geu-rim

Jo Ae-ran (53 years old), Geu-rim's mother who became blind during a surgery she had when she was 39.

Kang Hee-seok, a 55-year-old radio station director.

DJ Jay (Ep. 5)

"Gamoom"

Ahn Bong-seob, a 37-year-old reporter.

Jason, a 28-year-old psychiatrist who is Soo-ho's high school classmate and personal doctor.

Moon Seong-woo, a 57-year-old DJ of a thirty-year old radio program.

Ra Ra-hee, a 41-year-old radio program writer.

Jin Tae-ri, an over-the-hill actress who fell from grace due to a DUI accident that happened three years ago.

Lee Seung-soo, a 43-year-old radio program director.

Song Geu-rim, the writer of Soo-ho's radio show with five years of experience as an assistant writer. She lacks writing skills but possesses excellent planning skills. Lee Re as young Song Geu-rim

Lee Kang, the radio station's competent producing director. Because of his perfectionism, every program he handles achieved No. 1 in listener ratings.