Aries

アリエス

Aries is a timid female, very softspoken and shy. In the past, Karen the Celestial Spirit mage forced her to do many horrible things and generally abused her, such as using her as a shield (Because, apparently, she has no fighting abilities) and using her to lead away all of her boyfriends instead of simply refusing them.

Spoiler

Loke arc
Three years prior to the story, Aries was owned by Karen Lilica. In Loke's flashback, Aries was treated horribly by Karen. She used her to keep her "boyfriends" away from her. She tries to protest but she is too intimidated by Karen. Blue Pegasus Guildmaster Bob sees this and warns Karen to take care of her spirits. In a rage, she accuses Aries of ratting her out and apparently physically assaults her, although all that is seen is Aries getting shoved to the floor.
Karen threatens to keep Aries in the human world for a week, but before Karen can act on this threat, Loke steps in by summoning himself to take Aries' place (Since Karen could only maintain one spirit at a time) and tells the Celestial Spirit Mage to break her contracts with Aries and himself. When she refuses, Leo threatens to remain in the human world until she agrees, rendering Karen unable to summon any other Celestial Spirits. Karen continues to refuse, since she believes that he cannot remain in the human world for a long time; however, Leo leaves her with the ultimatum and goes to a deserted chapel where he stays for three months, attempting to get Karen to break the contracts. When Leo returns, he learns that Karen was killed on a mission and that Aries' key was taken.
Oracion Seis arc
After an exchange in the Spirit World, Aries is summoned to battle with Loke and Lucy Heartfilia. Despite the two not wanting to fight one other, they choose to fight for the sake of their pride, and the battle begins. However, due to Aries' non-combative nature, she fights a losing battle to Loke. As the battle progresses, Angel summons Caelum and uses it to blast through Aries and hit Loke, causing them both to return to the Celestial World for healing. After her defeat, Angel is arrested and her contracts with her spirits are broken. Aries, along with Scorpio and Gemini, seek out Lucy and form contracts with her instead.
Edoras arc
Lucy summons Aries to prevent the Edoras soldiers from capturing her and her friends. Aries then proceeds to attack the soldiers with a technique called "Wool Bomb", which allows Lucy and company to escape.