讲述即将出道的男子组合突然间回到过去，经过金赛纶的帮助顺利出道的成长故事。
Kim Sae-ron
Jung Ah-rin
차은우
Cha Eun Woo
문빈
Moon Bin
Kim Myung-jun
MJ
Park Jin-woo
Jin Jin
Park Min-hyuk
Rocky
윤산하
Yoon San Ha
서강준
Ah-rin's elder brother
추예진
[Herself / San Ha's girlfriend]
