Ryo has been the only Johnny to my knowledge that has been in 2 groups. Uchi Hiroki was in NEWS/K8 too, but he got suspended and is now a Johnny's Junior (
).
i miss you, Uchi! but work hard!
it's all up to the boss, really. the Kitagawas pick who debuts, who goes into what group, who's getting a drama, etc. they pick whoever's best for what task!
& yeah, they're not like H!P with temporary units. there's some special units like Shuuji to Akira where members from different groups interact, but it's usually for 1 single or something.
as for the jealousy issue, i don't think it's a problem. Ryo's in 2 groups and gets a lot of exposure, but i'm bet the others are really glad that they don't work that much!
