I think Andy's case is less like "fully leaving the group" and more of a hiatus-type deal. (At least that's what the SHCJs speak of it as.) But I dunno, I've watched a variety show that was released around this era and that treated it like Andy had fully left. I don't know for sure.
Anyways, girl group Diva had Ji Ni leave after their first two albums, but she quickly rejoined after their 3rd album activities wrapped up.
