Aya is a fair-skinned girl with straight black hair with bangs covering her eyebrows and dark maroon eyes. She is usually seen wearing her School uniform. When using her stick's powers, her eyes turns to hearts and the tips of her hair becomes red.
Aya is a shy, weak and lonely girl who suffers from depression and is always thinking of ending her life. She is always scared in some situations and gets frightened easily. She has a warm personality, she does not hesitate to protect her the ones she loves or care for even if it means risking her life, this was shown when she gathered with the other Magical Girls to use all the sticks on her own.
Aya was born shortly before midnight as the older of two twins, with her younger sister technically being born next day due to it being past midnight at the time. Afterwards, they were given up for adoption as their biological mother died during their birth, their biological father disappeared, and their real relatives did not want to take custody of them. As a result, Aya was adopted by Mrs. Asagiri after she lost her second child over a miscarriage caused by domestic violence from her husband. Mrs. Asagiri superimposed her with her stillborn daughter and raised her as if she were her own child. However, her adoptive father did not embrace her as his daughter out of his own stubbornness. Aya herself was kept in the dark about all of this.
At some point, Aya began getting physically harassed by her adoptive older brother, Kaname Asagiri. However, she chose to endure it as she was aware of the heavy presure his father placed on him. Around the same time, she was also badly bullied at school by Sarina Shizukume, Erika Kaijima, and Ai Kawano, which continued daily until she began contemplating suicide. However, she once again chose to endure it as she knew that without her acting as stress relief Kaname would surely snap under the presure and the entire family would collapse.
She has a gun with the ability to teleport to the people impacted by her feet where Aya's emotions changed. They can teleport to the place where Aya had strong emotions or feelings. While using her stick, blood flows from her eyes and her hair changes color. Her weapon was given to her by Nana.
A box cutter that heals the person who drinks the blood of the person who cut them self with the box cutter stick. She once used Kosame Amagai's stick to heal Kiyoharu Suirenji because she felt she was responsible for the injury of Kiyo.
A mechanical pencil where when you click the top, it Creates a box of light that is immune to any attack, magic or physical. She once used Mikado Ikemata's stick when she was fighting Sarina Shizukume to protect her and Tsuyuno Yatsumura.
- Aya is the first person to receive a Stick from Nana.
- Aya's stick is the first stick to be shown in the manga. She was also the first one in the manga to be shown using it.
- Aya's is shown to be either bisexual or lesbian as shown in Chapter 54 where she kissed Tsuyuno Yatsumura, but after the kiss the two didn't seem to show romantic interactions. This could of meant it might just have been a goodbye kiss shared between the two. Ironically they were revealed to be twin sisters, both not knowing this at the time and Aya learns this the hard way.
- She and Kayo Komura have similar traits:
- They both have a male character caring for them. Makoto Hinomoto for Aya and Takuma for Kayo.
- They are both the main protagonists of each story.
- They both made a friend who they became closer as the story progresses. Tsuyuno for Aya and Sakura for Kayo. In the former case they were actually long lost sisters.
- They both almost experienced rape, Aya was almost the victim of rape while Kayo's friend Takuma, was the victim of rape, though he was saved at the last minute.
- Her surname Asagiri/霧 means "morning fog".
- In the manga, Aya's stick's ability is to teleport the target/s to a place where she has strong feelings or emotions. In the anime, Aya's stick's ability is to teleport the target/s to any place she thinks.
- In Spanish playing cards, a heart ♡ means the clergy, which bring us the idea of the salvation, redemption, which completely fits with Aya stick's abilities (mainly the hidden one).
- In Chapter 102, she turned out to be an adopted daughter who was taken over by the Asagiri family.
- Her birthday is on April 8th, a day before Tsuyuno. The revelation in that they were twins means she was more a few minutes after.
- In Chapter 104, it's revealed that Tsuyuno is actually Aya's twin sister. Chapter 105 explains that their birth mother died and they were both put into adoption.