|Race||Will of the Planet|
|First Appearance||Ar tonelico Qoga: Knell of Ar Ciel|
|English Voice Actor||Tara Platt|
|Japanese Voice Actor||Yuka Komatsu|
Ar Ru is one of the greater wills of Ar Ciel. Her true name is Ar Ru. Her first priority is to preserve the life of the planet and she won't hesitate to re-format all life of Ar Ciel. In fact, she's very coy and shy. Along with her complicated personality, her preference in food is also very complex. Ar Ru really enjoys living on Ar Ciel and she dislikes stripping. Ar Ru's Hymn is Ec Tisia, sung together with all the others Wills of the Planet.
Role in AT3
Ar Ru is the Antibody Brain, the one controlling and making the antibodies. She fuses with Tyria when she is defeated. She has her own binary field, called DLC elemia island. She is a boss, and there is one time in which she can't be defeated. She is also a playable character later on.
DLC Elemia Island
In the binary field, Aoto and Ar Ru play as students from a high school going on a field trip because of their movie-making curriculm. Ar_Ru is the living sacrifice for the island.