Kanao is a girl of short stature, with large eyes and long black hair tied into a side ponytail with two strands of her framing her face. She adorns her side ponytail with a pink and green butterfly ornament similar to Shinobu's.
She wears the standard Demon Slayer uniform with a long pleated skirt instead of a hakama. For footwear, she sports a knee laced white boots. Kanao also wears a white cape with an ornament attached on the side.
At her introduction, Kanao is an indecisive and quiet girl. Due to the abuse she endured before meeting the Kocho sisters, she became unable to make decisions by herself and repressed her emotions as a defense mechanism. To help rectify this, Kanae gave her a coin to flip to decide which path to follow.
Between Kanae's death and the Functional Recovery Training Arc, she recovers slightly, but still relies on her coin to make decisions. She displays a somewhat mechanical response in conversations; when Tanjiro Kamado approaches her to bid her farewell, she repeats "Goodbye" when he attempts to continue the conversation. However, he eventually manages to start bringing her out of her shell and she starts to make her own decisions.
In her battle against Doma, Kanao takes uncharacteristically sadistic glee in pointing out his own lack of emotions. Fueled by hatred and spite towards her sisters' deaths by his hand, she attacks him verbally to the point where he drops his normal carefree demeanor.
Kanao lived an impoverished lifestyle before she was taken in by Kanae and Shinobu. Her parents were incredibly abusive towards her and her siblings, beating them and drowning them if they did anything they disliked. She broke psychologically, becoming an empty shell who was sold off into slavery.
As she was being led off, tied around the waist by a rope held by her purchaser, they were approached by the Kocho sisters. After confirming she was a slave, Shinobu distracts the man by flinging money in the air. When he releases the rope in surprise, they grab it and the sisters escape with Kanao to the Butterfly Estate. Soon after, the sisters discover the extent of her trauma, which makes Shinobu view her as useless, if not potentially dangerous. Kanae, unperturbed, gives Kanao a coin and instructed her to flip it if she ever needs help making a decision.
After Kanae was killed by Doma, Kanao was at her grave with the rest of the members of the Butterfly Estate. Although she was disturbed by her own inability to cry at her beloved sister's death, nobody judged her for it.
Kanao appears as one of the nearly twenty participants in the Final Selection, and is one of the five to survive.  She says nothing in her appearances, merely gazing at a butterfly and ignoring the commotion around her.
As Shinobu's tsuguko, Kanao accompanies her and Giyu Tomioka to Natagumo Mountain on Kagaya Ubuyashiki's orders. She pursues Tanjiro Kamado and Nezuko Kamado when they attempt to flee from Shinobu, successfully catching up and knocking an injured Tanjiro unconscious after he tells Nezuko to run. She catches up to Nezuko as well and tries to cut her head off, but Nezuko dodges by shrinking into child-size and continuing to run. The chase continues as Kanao fails to land her subsequent hits, and through all of it, Nezuko doesn't attempt to fight back. Though Kanao is left baffled at the idea of a demon not attacking humans, she decides not to ponder on it since her orders were to kill any and all demons. Once she receives orders by a kasugaigarasu to capture the siblings, she immediately stops attacking and asks the demon if she is Nezuko.
Thanks to his optimism and desire for her to open her heart, she is slowly opening up. It is hinted at, in an extra chapter, that he will become her "special someone."
Kanae took an interest in Kanao when she saw her being led away as a slave on the bridge. Along with her sister Shinobu, they purchased Kanao from her master and trained her within the Butterfly Estate. Kanae was the person who gave Kanao the coin she uses to make decisions whenever she is indecisive. After Kanae's death, Kanao found herself unable to cry at the funeral, but wears one of Kanae's hairpins as a memento of her.
Shinobu was originally against taking Kanao in due to her indecisive nature. Initially, she saw her as a useless, if not a dangerous person. Over time however, Shinobu warmed up to her, eventually even making Kanao her Tsuguko. Before the decisive battle in the Dimensional Infinity Fortress, Shinobu entrusted Kanao with avenging Kanae's death while she used herself as a sacrifice. Even though their revenge goes as planned, Kanao is nonetheless filled with hatred and spite towards Doma. After she and Inosuke Hashibira kill Doma for good, she fishes through the water to find Shinobu's hairpin as a keepsake of her departed sister.
Much like Shinobu, Kanao held strong resentment and hatred towards the Upper Moon Two for killing Kanae. This grudge grew even deeper after Doma devoured Shinobu following their duel, even if it was part of their plan for revenge. Kanao takes immense pleasure and satisfaction at calling Doma out on his inner "emptiness" and non-existent emotions, taunting him by asking him why he was even born and why he continued to bother living if he couldn't feel anything like a normal person would.
Abilities and Powers
- First Form:
- Second Form: Plum Spirit (
弐ノ 型 御 影 梅Ni no kata: Mikage Ume?) - A defensive techniques that deflects attacks using rotating sword slashes.
- Third Form:
- Fourth Form: Crimson Hanagoromo (
肆ノ 型 紅 花 衣Shi no kata: Beni Hanagoromo?) - A single sword slash that curves and twists.
- Fifth Form: Peony of Futility (
伍ノ 型 徒の 芍 薬Go no kata: Ada no Shukuyaku?) - A graceful flurry of nine consecutive attacks that flow and weave in on themselves.
- Sixth Form: Swirling Peach (
陸ノ 型 渦 桃Roku no kata: Uzumomo?) A technique used after or during evasion, the user spins around moving with their body weight to deliver an attack.
- Final Form: Scarlet Spider Lily Eyes (
終ノ 型 彼 岸 朱 眼Tsui no kata: Higan Shugan?) - A focusing technique that raises the users kinetic vision to its maximum, while using this technique the user perceives the world as if it were in slow motion. Usage of the technique however is highly dangerous, as the tremendous strain caused to the eyes ruptured blood vessels and could cause partial or complete blindness.
Superhuman Eyesight - Kanao possesses extremely sharp eyesight, being able to accurately predict her opponent's next attack and movements by simply observing the subtle shifts of their muscles, joints and the slight movements of their eyes. This allows her to make effective counterattacks and dodges and stay ahead of her opponents.The Upper Moon Two, Doma, complements on this feat and remarks that due to this skill, Kanao may be more skilled than Shinobu.
- This ability is enhanced with her Final Form: Scarlet Spider Lily Eyes Breath of the Flower technique.
- In the first character popularity poll, Kanao ranked 8th with 712 votes.
- Her birthday is in May 19th, which is the day Kanae and Shinobu adopted her.
- Kanao's main hobby is blowing soap bubbles.
- Her favorite drink is Ramune and she enjoys all of Aoi Kanzaki's cooking.
- It is noted that the hairpin she wears was one of Kanae's.