DAILY ANIME CHARACTER INTRODUTION : YUI OF ANGEL BEATS

Yui (ユイ, Yui) is a big fan of Girls Dead Monster, also acting as an assistant for publicity and other matters. She became the lead vocalist after Iwasawa disappeared. She had sung "Thousand Enemies" as a lead vocalist while the other song, "Shine Days", was not fully sung in the series, but only its chorus. Her singing voice is LiSA. 

APPEARANCE

Yui has long, pink hair with two bunches tied up with dark red laces, and two twintails on the sides of her face, but held together by small cross-shaped barrettes. She wears the same uniform as Yuri and the other girls although her shirt seems to be small enough to see her belly, and apart from regular socks she uses stockings. Though they don't seem to be in use, she also wears garters on each thigh.
On her wrists she sports single handcuffs with few slabs remaining on each (possibly, both parts formed a common pair of handcuffs). She wears wings that are hidden behind her hair. Another particular trait of her is her "demon tail" which seems to twitch and move whenever she is excited, happy, or emotional in any way. 

PERSONALITY

She is known to be hyperactive and talks extremely fast. Even within the members of the SSS, she comes off as very excited and loud. She recently became friends with Otonashi and Hinata. Also, despite acting childish sometimes, she can also be rude to her colleagues, although jokingly, as she sometimes throws trashtalk to Hinata and the others. She usualy tells the other SSS members that they're "morons". She is also a huge admirer of Iwasawa, because of her 'murderous' guitar gift.
Her upbeat personality is most likely inspired by her past life in the living world were she was paralyzed since she was 2 from head to toe. 

BACKGROUND

 In the living world, Yui was hit by a car when she was two years old. Due to this, she has been paralyzed from her
neck down ever since and was taken care of by her mother. Within the indefinite time she stayed in her room, she was usually seen watching television. Seeing different things on television became her only pastime, and she once wished of doing the things she watched when she manages to recover. Unfortunately, that time did not come.
It is unknown how she died, but it can be assumed that her body somehow broke down in some way. 

PLOT

 She briefly appeared in Episode 1 as a fan who was taking pictures of Girls DeMo. She was the fan who said Hisako and Iwasawa's names.
After Iwasawa's departure, Yui assumes her place in the band as the lead vocalist.
Upon being introduced to the SSS, she instantly gets along with Hinata, whom she usually gives a variety of wrestling holds to. Hinata always returns the favor, and at one time, he initiates the exchange. She was only seen performing "Thousand Enemies" as a diversion for "Operation Tornado". Although the only GirlsDeMo member (after Iwasawa's disappearance) to be in the Anti-Angel Headquarters, she does not contribute much in the missions, except as a diversion squad.
As the series progresses, Otonashi was able to fulfill her regrets. He helps her by doing the German Suplex, playing 5-on-1 soccer game (Maradona) and playing baseball (though she doesn't hit a homerun). After telling Otonashi that her last regret was marriage, Hinata later helps her fulfill her last regret by proposing to her, and giving her a vision of what could have been had they met in the real world. They'll meet when Hinata breaks Yui's window with a baseball, then he'll come and retrieve it and he'll start visiting more frequently, finally even relieving her mother of her duty to take care of her and they'll marry sometime after that. After thanking Hinata and Otonashi, Yui dissappears, having fulfilled her regrets and moved on, leaving only her baseball bat and the baseball helmet she was wearing at the time. 

•  Yui has little combat ability to the point even Yuri does not rate her as an effective threat against Angel, merely as a general distraction. However in non-combat situations, she displays surprising ability in wrestling (her favorite is "German Suplex" and she did this to Otonashi). She has caught Fujimaki with a heavy kick in a soccer game and Hinata in the second Guild Descent Operation.

 
 

 CREDIT : ANGEL BEATS WIKI