Tuareninya Veyron

Tsuareninya Beiron (ツアレニーニャ・ベイロン) is a maid apprentice of the Great Tomb of Nazarick under Sebas Tian's supervision and she is also under the protection of Ainz Ooal Gown. She is the older sister of Ninya.

Personality
She had very low self esteem and tend to dislike humans due to their treatment towards her, and is afraid of going outside due to the threat of recapture. She is greatly attracted to Sebas, and trusts him, even though he has previously attempted to kill her. After the trauma, she experienced in the hands of humans, she now prefers to stay away from human civilization.

Background
Tsuare was very close to her younger sister as she knows various things about her. Ninya mentioned that her older sister was taken by a noble but that she still doesn't know what happened to her. It became clear that she was sold into slavery. At some point she was sold to a brothel, and after severe abuse, was about to be disposed of when Sebas encountered her.

The Men in the Kingdom Arc
Tsuare was saved by Sebas Tian when she was about to be disposed by the brothel. She is later taken by Sebas to their mansion for shelter and was healed by Solution Epsilon. She became a maid in their mansion so that they can blend in better for their mission.

Tsuare was then evaluated by Ainz Ooal Gown himself, when he came to the manison to investigate Solution's claim that Sebas Tian had gone rogue. Ainz Ooal Gown wanted to erase the human's memories of her encounter with Sebas Tian and send her off, however when faced with possibility of forgetting her saviour the young woman refused, wishing to go with the old butler.

After she had told the Overlord of Nazarick her full name, it revealed her relationship with Ninya. She was later accepted into Nazarick due to Ainz wanting repay a debt to her younger sister, Ninya.

Sebas Tian
Tsuare is indebted to Sebas Tian, as he selflessly rescued her from her horrible life as a brothel slave. Being the first person to treat her as a human being, instead of an object or a toy, the young woman eventually became smitten with the aged butler. This affection towards him is to the point of willingly braving the potential dangers of Nazarick just to be with him.

Ninya
She is glad to leave the human world behind and go to Nazarick, but wishes to see her sister again. She still does not know about the death of Ninya.

Ainz Ooal Gown
Ainz considers accepting her into Nazarick as a form of repayment to her dead sister Ninya, since her diary allowed him to grasp some information about the New World.

Trivia

 * She is the first human from the New World that Ainz accepted in the Great Tomb of Nazarick.