She has lime green colored hair with teal colored eyes. She is introduced in a black cloak with a hood, but once she was captured and later released she wore a revealing green dress with blue earrings and cloth "arm covers?"
In her introduction she was silent and focused in her mission against Tachi and Rin, after she was captured she was uncertain as to what she should do with her life after her failed mission against Tachi. When she reunites with him she is shown to be kind, friendly, strong-willed as well as a bit mischievous and flirty but this was only with Tachi. She was very determined in her intention to be useful to help after Tachi helps her realize that she could have a life different from that of an assassin. She ends up falling in love with Tachi for not only sparing her, but for helping her find a new path in life.
So far nothing has been shown about her past other than her being an assassin prior to her meeting Taichi and the others. A female assassin who attacked Taichi and Rin while they were investigating a case for the Adventurers Guild in the city of Azpire. Captured by them, and with her life spared by Taichi, she renounces her profession and becomes a guild member, and forms a crush on Taichi for his compassion. Shortly afterwards she dies in a battle against a monster horde attacking Azpire, her abdomen was ripped off by the breath attack of the Twin-headed Dragon and she passed away in Taichi's arm , thereby helping Taichi to discover his true potential and strengthen his resolve to keep his friends and loved ones safe. .
While the full scoop of her abilities is unknown, she is seen to to have competent skills as an assassin in which she was able to cause trouble for Tachi before being dispatched by him, along with acting, information gathering as well as skills in breaking and entering. She also seems to have some basic medical skills due to helping treat the injured during the monster attack on Azpire.
Daggers - Anastasia was seen using two daggers in episode 3.
Anastasia means resurrection. She passes away around episode six in the anime, spurring on the main character to make a pact with a spirit. Because she was a former assassin, she felt guilt from the blood on her hands. Her name may give a prelude to either her becoming a spirit of resurrection or for her to someday become resurrected, along with possibly those she had slain. If or when this happens later on in the manga and anime, it would all be thanks to the overwhelming power of the main character's magic capacity.
- Taichi Nishimura: Anastasia is first introduced as an assassin and Taichi's enemy, she was defeated almost immediately but was spared out of kindness. Later on, after being released from prison, she was re-united with Taichi when he saved her from two men harassing her. She slowly starts showing signs of attraction up to the goblin war. She is then fatally wounded and was implied she was going to ask him out if she survived, she then changed her mind and asked only if they could be friends before passing away.