I personally don't mind having Koharu in. Sure, she seems kinda out-of-place, but I think she'll add some spice to the group. Whenenver the Momusu OGs appear on shows, it's usually some combination of the other 9, so having Koharu in will make things more interesting, I think.
(Plus she was in MM Tanjo 10nen Kinentai and I think she fit well in that, so I think she'll do fine here, too)
If Tsuji was in, I'd be even happier, but I'm still excited!
(Junjun and Linlin, too. ._. I wouldn't expect Eri to appear because she wants to deal with her skin condition, but I'd love to see Junjun and Linlin. Oh well. =/)
And while I love all of the girls, I'm mostly excited for Yossie. WOOOOO! (Rika, Yuko, and Miki, too, but mostly Yossie. xD)