"Inside my heart there was another me who was squealing while running around. There's no more mistaking it. I just have to admit it now. Seriously, seriously, seriously, my heart's seriously been stolen away. The arrow which had pierced my heart. The arrow of love which I could no longer take out. Is this even possible? Is it even fine for me to fall in love with someone who's been partly bullying me? But it's already too late. The power of this arrow is tremendous.

Kei Karuizawa is one of the heroines of the You-Zitsu series. Currently a second-year student of Advanced Nurturing High School, she is a prominent figure in Class D and is considered to be the girl's leader of the class.

Kei is a teenage girl of average height with waist-length blonde hair that is tied in a ponytail and purple eyes. Her school uniform consists of a light blue dress shirt below the red school blazer with rolled-up sleeves and a short white skirt. She walks in standard school shoes with light blue calf-length socks. She predominantly wears a blue ribbon around her collar. In a more casual situation, she simply wraps her school blazer around her waist and rolls up her dress shirt sleeves above the usual norm. She takes immense pride and care in having a pulchritudinous outward appearance and is known in the class to be one of the most fashionable and modish student in her class. During sports events she wears a white T-shirt, red sweat pants with a white stripe and white trainers.

At the start of the series, Kei comes across as a sloppy and spoiled girl who only cares about herself. She spends most of her time with the girls after school and uses her points to buy clothes and accessories. She is admired and feared throughout the class for her strong personality and her status as Yōsuke Hirata's girlfriend after only two weeks of entering the school, therefore establishing her position as the girl's leader of Class D. However, despite her looks and attitude she displays, she has her fair share of secrets that she cannot afford to reveal to others. She was unabashed and unashamed by the comments made by other people for describing her audacious moves on boys that caught her eye.

Underneath her pompous mask that she wears in front of people, Kei is a girl tormented by the ghosts of her past who can be weak and sensitive towards her surroundings.

(Looks like the love arrow struck Kei Karuizawa❤)