YAY ,
i think it's time to recruit some new members to replace mucchi and mano~
NO.
Think of it, OG usually is -except for a couple tracks in the album - Yossi/Rika/Konno/Mai doing the most singing and the rest working as mere backup singers. You don't want to add a couple girls to become dead weight (or, in the case of Miki, to steal the spotlight. Give her the damn solo career she deserves and leave the rest).
Unless they're giving the Eggs some good lines in the following songs, it's unwise to add more girls since they'll barely go noticed.
Plus, I'm getting tired of "supergroups". OG is awesome because its current members are so funny and give such a good feeling, not because they're DEF.Diva v. 2.0.