The story follows the antics of four high school freshman girls, after they enroll into a huge private academy that teaches every grade from elementary school to high school.

i read the manga, like the mangaka other work, i really like how the story flow. Though i think its better they do his other one which involve extreme bro-con elder sister who obsess with her brother into anime instead, but heck i done reading that, n only Hyakko i read only for 1 chapter only .
neway i knew bout the anime thingie, just wanna make this thread for future use. i still not sure if Soviet gonna attack this series with their massive naval army of nuke-submarine yet.

the development (jap) : http://flex-comix.jp/hyakko/2008/03/post_5.html
It seem October only aired (2 months to go i guess)