This is Chise (ちせ) from the Saishuu Heiki Kanojo (最終兵器彼女) or in short Saikano series. This is one of my favorite anime. This figure was initially released as a cold cast from Kotobukiya in May 2001. I was not able to get it from Yahoo Auction Japan because the bidding price on it was always extremely high. So I was really happy when I saw the news that Kotobukiya will release Chise as a PVC figure.
Kotobukiya 1/8 Saikano Chise PVC (壽屋 1/8 最終兵器彼女 ちせ). Original sculptor 白髭 創. Released on August 2005 with a MSRP of ¥5,040.