Height: 156 cm
Weight: 50 kg
Blood Type: O
Sign: Sagittarius
Birthday: November 27
Age: 15-18

Favorite Music: Yui doesn't follow any particular style, and isn't picky. As long as she likes it, anything is OK.
Experience with musical instruments: Castanets
Family Structure: Family of four, both parents and younger sister (Ui). Father works for a trading company, gets a lot of overseas assignments and tends to be absent. Because the mother often travels overseas too (helping the father), the daughters have many opportunities to spend time alone together.
Dwelling: Single family detached home.
Commute to school: Walking.
Preferences in clothing: Pants over skirts. Yui is relatively fashion conscious and likes styles featured in teen magazines. She also wears casual clothes such as shorts and T-shirts at home.
Her room: Clean, because Ui cleans it. Yui likes small cute things, and keeps stuffed toys and such in her room. The room is painted in girly pastel and pink tones.
Favorite food: Anything, as long as it's sweet and delicious.
Subjects she is good at: Between low and average and can rarely pass test easily, but has a hard time with questionnaires.
Subjects she is bad at: All of them
Physical exercise: She can do it, but hates getting tired.
Way to pass time when alone: Lazing around at home.
Weaknesses and dislikes: Studying.

Main character, guitarist, lead vocalist. Having misunderstood that "light music" equals "easy music" (like whistling), she joined the Light Music Club and picked up guitar with absolutely no prior experience. She is the type of person who doesn't read manuals and relies on her own intuition and self-taught approaches.

Yui is the lead guitarist and split vocalist of the Light Music Club who plays a Heritage Cherry Sunburst Gibson Les Paul Standard electric guitar that she nicknames "Gīta" (ギー太). Before she learned how to play the electric guitar, the only instrument she knew how to play was the castanets. She gets poor grades in school (though when properly coached, she can achieve astounding results), spaces out frequently, and is easily distracted by trivialities (mainly those she deems cute). Yui is a kind and friendly girl who holds no ill-will towards anyone. Yui has shoulder-length, brown hair (a little longer than Ritsu's) which she accessorizes with two yellow hair clips, and brown eyes. She has a huge liking for sweets and consumes them frequently (though she never gains weight, which is greatly envied by Mugi, Mio, and Sawako). She has a younger sister named Ui, who is very mature and acts as the "older sister" of Yui, taking care of her while their parents are away on business trips. Despite her difficulties with distractions, Yui works extremely hard to get better at playing guitar. During performances, Yui plays with amazing energy and joy which usually results in great response from the audience.

As a musician, Yui has absolute pitch—she can tune her guitar perfectly without a tuner, which greatly impresses Azusa, who possesses far more experience with playing guitar than Yui. She has a very easy-going nature, but has incredible focus and retention when she has a clear goal in sight. Yui is still devoted to her band and will always practice hard enough for the club. At school, she has become quite admired for her great voice. However, she has been shown to forget her lyrics mid-performance on at least one occasion and exert herself too much, making her unable to perform sometimes. Mio was the lead vocalist at first, since Yui could not play the guitar and sing at the same time.

(Source: Wikipedia)