She's the Aogiri's maid. She's usually shown as a comic relief. She doesn't possess much role in the series but by driving them around and helps taking care of the house, but I tell you, she can really drive fast!
Ceres, Celestial Legend (妖しのセレス) is a fantasy shōjo manga series written by Yuu Watase. It was originally serialized in Shōjo Comic from May 1996 through March 2000. The chapters were also published by Shogakukan in fourteen collected volumes. The series focuses on Aya Mikage, who learns on her sixteenth birthday that she is the reincarnation of a celestial maiden (天女) named Ceres, and her twin brother Aki the reincarnation of Ceres' former husband. Ceres begins manifesting in Aya. To try to save her brother, Aya must find Ceres' lost celestial robe (羽衣), while trying to avoid being killed or captured by her own family, who wants to use Ceres powers for their own gain.
The manga series is licensed for English language release in North America by Viz Media. In 1998, it won the Shogakukan Manga Award for shōjo. Studio Pierrot adapted the series into a twenty-four episode anime series that premiered in Japan on WOWOW on April 20, 2000 and ran until September 28, 2000. The anime series is also licensed for Region 1 release by Viz Media.