Edit: And btw is it just me or Hinata has recently used a "more feminine" voice than she used to ? I have noticed it since the Ebichu no Omocha Garage concert :))
Are people following the radio shows? Hinata was in top form this Sunday.
Spoiler:
M: right, next time Hinata comes on, she'll sing MX. H: why? M: cause I sang it the other day and it was hard. R: don't make other people suffer, too!
M: whatever, let's do it today. Sudden change of plans! M: we'll just cut me singing Kiroro's Mirai he.
R: your fans will be sad M: everybody is fed up with my voice, as far as I ... H (interrupts): what are you doing with that CD! (staff laughs) H: don't you dare! R: ...is what she says, but really she wants to sing.
OK -- just to be on the safe side, this is 高校卒業 for all of the idols listed at the end, and not 私立恵比寿中学卒業 for Mayama? (Since the list includes Mizuki, who just became leader of MoMusu, it can't be group graduation! I think...)