Muu

Muu (むー), known as Muu-chan (むーちゃん) to her friends, is a minor character introduced in Toaru Kagaku no Railgun. She is a Level 0 student of Sakugawa Middle and is a user of the Level Upper.

Appearance
She has short brown hair, with fringes that are parted slightly on the left side of her scalp. Though not often seen, she also seems to have a small fang.

Background
She is currently enrolled in Sakugawa Middle and is a classmate of Saten Ruiko and Uiharu Kazari. She is usually seen with her friends Akemi and Mako, both of whom are also in the same class as her.

Level Upper Arc
In the anime, she first appears in class listening to a lecture about Personal Reality. She later appears alongside Akemi and Mako, wondering about the Level Upper and bemoaning the fact that she lacks enough money to afford its high price. They then run into Saten Ruiko, who has the Level Upper and shares it with them. She then uses the Level Upper, allowing her to improve her abilities. Her next appearance is in a park, allowing Akemi to use her powers on her. Akemi forgets that she was using her abilities on Muu and drops her on the ground, making her mount Akemi's back as revenge (in the manga, she also tries to choke Akemi with her arm). In the anime, she practices her powers on cans and later runs to Akemi after the latter collapses due to her using the Level Upper. She eventually collapses as well as a result of using the Level Upper and is sent to a hospital.

She reappears in the anime alongside her friends in a special class for users of the Level Upper. Later, she joins the rest of the students in running laps around the track as part of training under Yomikawa Aiho. During Ruiko's confrontation with Elder Sister, Muu is concerned about Ruiko's well-being but doesn't do anything. After Elder Sister leaves, she criticizes Ruiko for taking on Elder Sister and asks her if she knows no fear. She agrees with Akemi's statement about Ruiko saying that cheating is wrong. After the special class, she is told by Mako that her statistics rose and comments that her own rose as well. She later joins Akemi and Mako for a party to celebrate.

Poltergeist Arc
She, alongside Akemi and Mako, appear briefly in a flashback where they celebrate Kazari's induction into Judgment. Her final appearance in the anime is in a park somewhere alongside Akemi and Muu, looking at Kiyama Harumi's birthday present that was prepared by her students.

Dream Ranker Arc
She appeared briefly in the background when Saten communicated via Speech Bubble with Frenda Seivelun.

Abilities
Her ability is never shown in the manga, but in the anime, she displays the ability to levitate a few cans off the ground after using the Level Upper.

Trivia

 * She does not refer to Ruiko by her family name, instead using her given name; this indicates that she is very close to her.