- Japanese Voice Actor: Yuri Ehara
- English Voice Actor: Reba Buhr
- Age: 16
- Manga Debut: Chapter 48
- Anime Debut: Season 1 Episode 23
- Race: Human
- Gender: Female
- Status: Alive
Like most demon slayers in the series, Aoi lost her family when the demons attacked them. She was then taken to the Butterfly Mansion and worked as an apprentice under Shinobu Kocho. She is a part of the butterfly mansion and is even responsible for the name of Kanao.
Kanae and Shinobu do not know which name they should give her. They wrote different names on the piece of paper, and when Kanao was supposed to pick the paper containing the word “Kamasu,” Aoi changed it and put it with the word “Kanao.”
She is well-versed in medical knowledge, but she lacks confidence. She always reiterates to people that she is not as useful as the full-fledged demon slayers and that what she does is not much of a contribution.
She was able to pass the Final Selection. She did not become a demon slayer because she attributed her passing the exam to pure luck. She does not have confidence in her ability to fight and defend despite being a Water Breathing style user, so she opts to become a healer.
This was the best decision for her as she was regarded as one of the best healers in the series and one with vast knowledge of medicine.
Aoi was first seen during the Rehabilitation Arc. She was one of the people who took care of the group of Tanjiro. Her vast knowledge was proven useful when she could repair the box of Nezuko that Sanemi cut. Aoi was the one responsible for Tanjiro, Zenitsu, and Inosuke when they were brought to the butterfly mansion for recovery.
She is the strictest person in the Butterfly Mansion. This is no surprise, as she is responsible for her training regimen. Aoi is capable of analyzing the need of the patient and designing a training regimen for them to recover quickly and learn new skills.
This was shown when the trio was brought to the Butterfly Mansion, and she created different training exercises for them to recover quickly.
Aoi was the one who always took care of the trio when they were injured. After the Mugen Train Arc and even during the fight in the Red Light District, she cared for the trio when Tengen picked Aoi to go undercover in the Red Light District.
Tengen even called her a useless member of the Demon Slayer Corps. When Tanjiro interrupted Tengen, he explained to Tanjiro that he needed a female demon slayer to go undercover. Upon hearing this, the trio volunteered in her place.
Inosuke had always been harsh on Aoi. When Tanjiro and Zenitsu beat her, they did not pour the tea on her, saying she was a lady. Inosuke did the exact opposite. After volunteering to go undercover in the Red Light District, their relationship changed.
After returning from the mission in Red Light District, Inosuke was badly poisoned. Seeing Inosuke, Aoi was sad and thought it was too late to stop the bleeding. As her tears start to fall, it is shown that Inosuke is not that hurt at all and is still capable of messing around.
It was implied in the manga that Aoi and Inosuke ended up together. Aoba Hashibira has the kanji of Aoi’s name and has the last name of Inosuke. Aoba became a botanist and had the same hair as Aoi. Though the relationship between Inosuke Hashibira and Aoi Kanzaki is not confirmed, the appearance of Aoba in the last chapter of the manga had fans speculating that Aoi and Inosuke ended up together.
Aoi is shorter than an average girl. She has the typical height of a tsundere anime girl. She has straight black hair that is parted and tied into twin tails. These twin tails are held in place by a butterfly clip. She wears the standard demon slayer uniform. Over her uniform, she wears a white nurse dress and a blue sash around her waist.
Aoi seldom smiles. She is a strict teacher who always wants things done her way. She would shout at people for failing their training. Aoi would stop at nothing until her students succeeded.
She is useful when most tsundere anime girls are useless and do nothing but shout and complain. Her knowledge of medicine had proven time and again how she could save the lives of her fellow demon slayers.
She had been looked down on by many demon slayers for being unable to fight. She pays no heed to whatever other people think, as she only wants to help them when they are in distress. She cares so much for her family and friends.
Despite not being able always to express her feelings, some events allow her to show her emotion. She cried when Inosuke was as good as dead after infiltrating the Red Light District. Another incident was when she showed how much she appreciated the stay of Tanjiro, Inosuke, and Zenitsu in the Butterfly Mansion.
She is a Water Breathing style user. After passing the final selection, she opted not to be part of the Corps but instead helped in the Butterfly Mansion. Despite not having confidence in her swordsmanship, she has a good fighting ability.
She does not spend any time on personal training and missions. She does not have to carry around a Nichirin Sword as most demon slayers as this is not needed in her current job.
Aoi has excellent research ability. She works with Shinobu in creating medicines and potions that could greatly help the other Demon Slayer Corps members when they get injured. She does not do physical training, but she does a lot of training under Shinobu in creating simpler medicine that acts as first aid for demon slayers.