some idols, once they were in a group or supposed to debuted in a group. but those idols were stepping down for some reason and join a new group! these are those idols
Hyuna - Wonder Girls -> 4Minute
Hyuna debuted as Wonder Girls in early 2007, but she stepped down in July 2007 due to her health problems; chronic gastroenteritis and fainting spells by her parents request. After 2 years hiatus, she was transferred to CUBE-Ent and re-debut with 4Minute with 'Hot Issue'. I believe in 2 years hiatus while recovering her health she trained a lot too, cause now she was like one of the best dancer in k-pop industry.
Hyuna with Wonder Girls (short hair)
With 4Minute
Hyunseung - Big Bang -> BEAST
He's haven't officially debuted with Big Bang yet. But he was supposed to debut with Big bang, he even already have stage name 'SO-1', but he was eliminated during the finalization of Big Bang. YG have chosen Seungri instead of him. He even said that he's having a very hard time after being eliminated from Big Bang, he feel extremely lonely, cause he already made lots of memories with Big Bang members. However he managed his difficult times, move on and finally debuted with BEAST from CUBE-ent
Hyun Seung with Big Bang (at the back besides Daesung)
With BEAST
Soyeon - SNSD -> T-ara
I don't really know about T-ara, but from what i heard she is the main vocal in T-ara and she was supposed to debut with SNSD, but she decided by her self to stepping down from SNSD because she have lack of determination and confidence at that time. I believe in 2 years she manage to built up determination and confidence and finally debuted with T-ara from Mnet Media in 2009
With SNSD (she is standing, second one from left, black shirt)
With T-ara
Chan Mi - SNSD -> Co-Ed
Co-Ed is a new group from Core Content Media, who just debuted on late September 2010. As far as i knew Co-Ed is now the only mixed k-pop group, they have both males and females as members. One of them, Chan Mi was supposed to debut in SNSD. As we all know SMent revises the arrangement of SNSD for a few times due to various reason, maybe i should discuss how SNSD is formed later. I'm noyt sure about the reason why she choose to stepping down from SMent/SNSD. But i believe it's because she have different interest. And there's also a rumor that she was supposed to debut with f(x), not sure about this but the SNSD ones is true
With SNSD
Co-Ed
Soyu - 4Minute ->SISTAR
From some k-pop news i read, i can conclude that Soyu is SISTAR best vocal, cause she sings an OST for Playful Kiss by herself. No wonder if Soyu is SISTAR best vocal, cause she actually already prepares and practiced to be a singer for a long time, in fact she was actually trained to be a part of 4Minute. But unfortunately, she get rejected a few days before 4Minute debuted for some (currently) unknown reason. She made a close relation with 4Minute members during trainee days, that's why she shows some emotion when she finally debuted with SISTAR by encouragement from her old friend, Hyuna.
Hye-Lim - Miss A -> Wonder Girls
Sunmi replacement, she was actually trained with Miss A and was planned to debut with Miss A (formerly, introduced as 'Wonder Girls China Version' and was planned to have 5 members too) but because of Sunmi leaving, JYP decide to put Hye Lim in WG and let Miss A with 4 members. A video of her dancing with Miss A members (w/o Suzy & Min) has been revealed before she was finally become a WG members.
With Miss A
With Wonder Girls
that's all i know
