Asa Mitaka is the main protagonist of the Academy Saga. She is a high school student who became the host of the War Devil, Yoru, making her the inhabitance of the War Fiend, though she still retains her human personality when the War Fiend allows her control, making her a rare case of a living Fiend host. She attends Fourth East High School with Denji, with whom she attempts to start a relationship with. Asa is a high school girl of average build and height. She has brown eyes that are usually pitch dark, though the irises become much brighter in some situations. Her hair is black and is sometimes colored with a purple tint. The hair reaches the middle of her back, and she wears it in two low twin tails, making it appear shorter. In the past, Asa wore her hair at shoulder length. She wears the same school uniform as the rest of the girls in her class. The uniform consists of a long-sleeved button up shirt worn beneath a pinafore style dress with a pleated skirt that extends below the knee, a bow at the collar, a wide belt at the waist, and black, knee-high socks. She also wears sneakers. Asa is initially a quiet and unsociable girl. She dislikes her classmates, frequently wishing they would drop dead and spurning any offers of friendship. She has a very negative outlook on the world, other humans and Devils and tends to assume the worst of others. She is however very fond of cats and would rather kill a human. Asa later admits to herself that her mean-spirited altitude towards her peers was a result of jealousy. She also suffers from low self-esteem, considers herself a clumsy individual. Despite this Asa can be falsely self-assured and overconfident such as her belief that she would easily be able to seduce Denji. Asa can be extremely socially inept, such as believing that boring Denji with ocean facts on their aquarium date would be a great way to win his affection. Her moral compass is somewhat artificial, as she is often more worried about the consequences certain actions carry instead of the actions themselves. For example, she doesn't feel bad about having accidentally killed Bucky but feels bad because of the looks her peers gave her. This also gets reaffirmed in the aquarium, where Asa refuses to kill Denji after being trapped and starved for several days. She doesn't do so because it goes against her morals but because she does not know what is right and wrong and constantly tries to avoid making mistakes. Mitaka's fairly altruistic, putting herself in harm's way to save others even when she is afraid. Asa would be willing to endure bad situations if only she were to suffer, but refuses to drag others with her. After being saved by Chainsaw Man, she realizes she's glad she's not dead and is no longer as negative towards other humans or towards all Devils. However this was short lived as she easily fell back into depression and even attempted suicide during the Falling Devil fight. Asa doesn't cope well with failure or when things don't go her way. Because of past experiences she is extremely afraid of making mistakes. Once she does make a mistake she usually get's very angry blaming everyone around her except herself. Though after calming down she'll break down in self-deprecating rants. She seeks validation as shown by her internal monologue during her meeting with Yoshida or breaking down and seeking comfort from Yoru despite being afraid and screaming at her mere moments prior. She has trust issues yet is afraid of loneliness but is also afraid of trying to approach someone as she believes she'll mess up and end up lonely again. This puts her in a cognitive dissonance as she puts it where she's afraid of both solitude and companionship. She has a negative opinion on sexual intercourse. When Chainsaw Man reveals his main drive in life is to have sex, she openly expresses disgust. She believes people only have sex when there's nothing better to do, and the thought of mixing her saliva and sweat with someone else sickens her.