Quoted from Hello Project's producer Tsunku's blog ...

「はい、というわけで、久住小春の卒業に関して
発表させていただきました。

ファンの皆さんを驚かせてしまいましたが、
こういうのは結果突然でしか発表出来ないので、
ご容赦ください。

久住も、戸惑いながらもキチンと受け入れ、
彼女のコメントにもあるように、とても前向きに
次の新たなる自分へ期待しているようですし、
１２月６日までのモーニング娘。
ツアー「モーニング娘。コンサートツアー2009秋～ナインスマイル～」が
終了するまでモーニング娘。としてがんばって行くと
気合が入っています。

なので、どうぞこのツアーを見逃すことなく、
全国の皆さんは楽しんでいただきたいと思います！

どうぞよろしく！」　

Which roughly translates to ...

「As you know, the announcement regarding Kusumi Koharu's graduation was made.

Although all of you fans are shocked with this news, it is hard to announce such an unexpected event under a better light,so please forgive.

Although she was dumbfounded,Kusumi accepted it quickly.As per her statement,she is looking forward to her new future.She'll continue working hard as a Morning Musume member till [Morning Musume's Concert Tour ~ 2009 Fall ~ Nine Smiles] ends at 6th December.

Having said that, don't miss this tour, and hope everyone have a great time. 」

Well I guess Koha's graduation decision wasn't brought up by herself after all.Else she won't be surprised and shocked that she's the next one graduating out of Momosu.

Having read quite a number of forums and seeing various reasons,some weird and some "lol wut", it limits down to 3 reasons I guess ...

1.She isn't enjoying and loving her job in Morning Musume anymore.So the company decided to release her.

2.Company has no further use of her now that her role in Kirarin Revolution is over.

3.There's an internal conflict between Koha and the other members and hence the company decides to remove her to prevent any further tension from rising.

Honestly I doubt it's any of them.Seeing that she's still a popular member and the link between all the Kirarin Revolution fans to Morning Musume shows that she still brings something to the publicity image of Momosu.And internal conflict ... spending quite a fair bit of "behind-the-scenes" time alone just isn't sufficient reason that she's not socalizing well with the other members.And I honestly doubt there's a fall-out between the members anyway. I don't see any recent events or anything that can honestly buff up the ego of Koha to such an extent that she can get into an argument with her teammates regarding publicity.

Bit by bit ... bit by bit ... the real reasons behind Koha's sudden graduation are emerging. Even if it's something demeaning done by her I'll like to know. If it's the company who's the one that decides to push her out I'll like to know as well.