Habuko’s most prominent feature is undoubtedly her head and neck, which, rather than being a regular human shape, is instead that of a gray patterned snake, with bright yellow eyes, slits as their pupils, with a shock of spiked, shoulder-length red hair around the top. Despite this, however, her body is of a regular human shape, and is quite petite with fair skin.
She wears the Isamu High uniform, which consists of a white dress shirt with a dark red bow tied below the collar, over which is a dark blue blazer and below is a pleated, gray, knee-length skirt, below-the-knee socks and plain brown loafers.
Her hero costume consists of a blue bodysuit with a high collar and attached high-heeled shoes, a snake pattern running down her arms and legs. She has darker blue straps around her shoulders, a section over her torso like a snake’s chest, and she wears a long piece of yellow cloth tied around her waist, a split yellow-tinted visor over each eye.
Habuko considered herself to be a treacherous and disagreeable person; this perception of herself stemmed from her lack of self-esteem caused by her loneliness. However, after becoming friends with Tsuyu Asui, she became more sociable and friendly. This is shown by the photo she was in with her high school friends.
Two years before Tsuyu became a U.A. student, Habuko was a student attending the same middle school as her. During her time at middle school, Habuko started stalking her. Habuko often used her Quirk, which paralyzed whoever she looked at for three seconds, on Tsuyu. Despite this, Tsuyu wasn't bothered by Habuko's stalking because she could understand her since they were both lonely.
One day, Tsuyu mustered up the courage and asked Habuko to be friends. Habuko was touched by Tsuyu's kindness and agreed to be friends with Tsuyu. Eventually, Tsuyu and Habuko graduated from their middle school but went to different high schools.
A day after U.A.'s new school year began, Habuko sent a message to Tsuyu, telling her that she has made new friends at her high school and promises to introduce them the next time they meet.
Paralysis: Habuko's Quirk gives her the ability to paralyze her targets for three seconds, making them go limp. She activates this power by staring into her targets eyes. The victim remains conscious while immobilized.
Habuko was a student who attended the same middle school as Tsuyu and was the first friend Tsuyu made. They had many similarities to each other: having strange appearances that made it difficult for them to make friends and the loneliness that followed. Often, Habuko would stalk Tsuyu, but not with ill-intent. Tsuyu did not mind this because she understood Habuko's loneliness resulting from her appearance. Eventually, Tsuyu asked to be friends with Habuko. Touched by her kindness, Habuko agreed. They graduated from middle school together but went to different high schools. Even though they are at different high schools, Tsuyu and Habuko never stopped being friends with one another as shown when Habuko sent her a message and when Tsuyu herself noted that Habuko will always be her friend. Their friendship became a catalyst that helped them socialize more and make new friends in their respective high schools.
- "Habu" (ハブ?) is the name of a specific species of snake native to Japan.
- Her surname is ironic considering that mongooses naturally prey on snakes and some being resistant to snake venom.
- Her Quirk's ability is a reference to Medusa, Cockatrice and Basilisk, all of whom have the ability to turn their victims to stone by looking at them. Her appearance further references these creatures, as all these monsters are based on or related to snakes in one way or another.
- Her Quirk also references the expression 蛇に睨まれた蛙, "a frog glared at by a snake", meaning "to be paralyzed in fear", which is quite fitting of her character since she is friends with Tsuyu, who is very frog-like.
- This is the only Isamu Academy High School student to be introduced in the manga instead of Training of the Dead.