Risako as the next Ayaya is quite possible but who would be the next Miki for GAM mk. II?
I think they're actually grooming Miya to be the next Ayaya (in the term of H!P top singer soloist, not as an idol). Risako might get Meccha Holiday in this album, but Miya got to sing Matsuu songs solo twice and always got her lines. As for Risako, I still can't see which way she's heading to. But she's very young, we'll have to wait for a while, I think.
I really noticed that she gained weight when I saw the Nyouki Nyouki Concert. She's lost most of it now though. I also noticed that's she the shy one in the group. She rarely talked in the H!P DVD Magazine Vol 7.
To me, Risako is more a a "my pace" type. Like she doesn't really care what's happening around her.
Miya's the shy one. You can see the difference when she's with her friend and when she's with her senpais and whoever.
I think I talk more about Miya than Risako here. :p