"A star that disappeared 24 years ago without a trace suddenly resurfaces as the neighborhood's unemployed slacker."

23-year-old Yoo Hyun-jae (played by Yoon Shi-yoon) is a member of the group J2, which swept the Korean music world by storm in 1993. He disappears with the wind "Kaola" (meaning "time" in Hawaiian) leaving not even a trace. He arrives in 2017, 24 years later, face to face with his 23-year-old son. It's a coming-of-age story revolving around those in their 20's in this generation.
(First broadcast: Friday, June 2, 2017)

Yoo Hyun-jae (23 years-old) - played by Yoon Shi-yoon
Member of popular 90's group J2.
He can compose music, dance, and sing. He's a Mozart-like genius that takes the Korean music scene by storm. One day, he suddenly disappears without a trace and reappears in the year 2017, shocking everyone.

Choi Woo-seung (23 years-old) - played by Lee Sae-young
Due to her mother's many marriages and divorces, Woo-seung's dream in life is to simply have a stable life. One day, she loses her boyfriend to her best friend and finds herself living with Ji-hoon, a guy that has a crush on her.

Lee Ji-hoon (23 years-old) - played by Kim Min-jae
He dreams of becoming an idol singer, but due to his straight edge personality, the 3-year singer trainee is about to get eliminated from the group set to debut. One day, he coincidentally runs into his father Hyun-jae and ends up picking up on Hyun-jae's talents and charms while living with him.

Lee Gwang-jae (46 years-old) - played by Cha Tae-hyun
He used to be a successful talent manager in 1993, but ends up as the CEO of a non-successful entertainment agency called World Project. He registers Ji-hoon, who is the son of his first love Bo-hee, as his legal son. For over 20 years, he silently protects and loves Bo-hee.