Name: Haruhi Fujioka (藤岡 ハルヒ, Fujioka Haruhi)
First appearance: Ouran High School Host Club (manga in 13 volumes - still ongoing - and anime - 26 episodes)
Creator: Bisco Hatori
Age: 16 years old
Haruhi is a student at the very prestigious Ouran High School. She is a commoner, able to go there through a scholarship. By accident she walks in on the Host club - a club kept by six male students at the school to keep the ladies entertained. She breaks an expensive vase, and since there was no way she could repay it she had to work off the debt. Her sex was not viewed as a problem, because they did not know she was a girl. She could not afford to buy the school-uniform so instead she had borrowed clothes from her father - and she had gotten gum in her long hair so she had cut it off. The truth is soon revealed, but she stays on, posing as a boy (something that she had little problem with, being of the opinion that gender makes little difference).
Haruhi is a blunt person, intelligent and a good student, a popular host - and blind to the verge of down-right stupidity when it comes to relationships. There are quite a lot of guys who falls for her, like the successor in a yakuza family Ritsu Kasanoda (who has some serious problems with that when he first thinks that she is a he), the twins Hikaru and Kaoru of the Host club (though it is only Hikaru who actually confesses to her - and he is turned down) and the president of the club, Tamaki Suoh (though he is very slow at realizing that himself - making them a good match in that respect).
Haruhi lost her mother when she was young and lives alone with her cross-dressing father who works in a bar. Their life is very ordinary and the upper-class boys of the Host club is fascinated by that - though it annoys her. She does have one friend form outside of school that shows up in the manga, Mei - the daughter of another cross-dressing man. She has very little problem seeing what Haruhi is feeling - even when she does not know herself.