What awful news.
Mizuki: Bummer but not terribly shocking. She's one of SKE's mood makers but always kinda been in the middle to back, senbatsu-wise.
Shiitan: Underrated, underused girl, and now she's gone. She's one of the "Management WTF she's awesome why not use her" girls in my list.
Kanakana: Poor girl lost her senbatsu spot when she got injured and never really got it back. :/ Bummer.
Ririna: Not very surprising, she got practically nothing in SKE48 except a lukewarm theater spot.
Kasusu: Damn, too bad. Girl had epic gravure potential and was generally entertaining.
Haramina: A great talent and she just sat there for the most part. What a waste. That's the one thing I can't stand about SKE48, Team E has so many great girls and they all just sit in the theater. UGH.
Emiri: She was cute but I didn't know much about her. I saw someone mentioned she said her dad died. That's really sad.
And finally, Ogichan: I have no words, my SKE fandom has been hit harder than ever. I haven't ranked in a while but she's definitely top 5. I had just recently seen the Shukan AKB episodes with her, Kinchan, and Matsurina. She's just such a lovely girl that brought a wonderful aura with where whenever she appeared. I am really, really sad to see her go.