From KyoAni and the same staff behind Kanon, Air and Suzumiya Haruhi no Yuutsu

Clannad

Cast
Mai Nakahara (Naminé @ KH2, Mai @ Mai-Hime/Otome) as Nagisa Furukawa
Ai Nonaka (Konoe Konoka @ Negima) as Fuuko Ibuki
Akemi Kanda (Kagurazaka Asuna @ Negima) as Ryou Fujibayashi
Houko Kuwashima (Sai @ Angelic Layer, Minoru @ Chobits) as Tomoyo Sakagami
Mamiko Noto (Toujou Aya @ Ichigo 100%, Miyazaki Nodoka @ Negima) as Kotomi Ichinose
Ryou Hirohashi (Franca @ Coyote Ragtime Show, Anya @ Negima) as Kyou Fujibayashi

ANN
Official Page

More info will be revelead March 20. Rumour states it will air in October 2007