Akeno Himejima

At the tender age of 10, without food or money, Akeno journeyed throughout Japan using her skills to purify evil spirits that she learned from her mother in order to survive, doing so for one and a half years. When she stumbled into a certain town, Akeno indirectly saved a human that was contracted with a Devil from the Gremory Clan. Fearing that the Devil would kill her due to her Fallen Angel heritage, Akeno decided to hide from them. Later, while trying to leave the town, Akeno was suddenly attacked by her relatives from the Himejima Clan who came to kill her. Before her Grand-uncle could land the decisive blow, Rias and her father's Bishop, Heinrich Cornelius Agrippa, appeared and talked Akeno's family out of killing her with two conditions, first Akeno is to never enter the territory under the Himejima Clan and second, to always stay beside Rias and serve under her using the Gremory name and not the Himejima name. She then moved into the Gremory Palace where she was taught various things from studies to how a lady should act as well as deepening her bonds with Rias, becoming her best friend in the process.

Upon entering Junior High, Rias received her Evil Pieces and made Akeno her first servant. She later entered Kuoh Academy alongside Rias and helped her in re-establishing the Occult Research Club becoming its Vice-President.