Haruhi

The title goes something like this:
- "I realized I wasn't the female lead/protagonist"

Summary:
- The boy and girl knew each other since kid and the girl had like a crush on the boy always thinking of herself as the female lead and him the male lead not until high school where another girl came.

Character desc.:
- Girl is curly blonde with a personality like the sun
- boy is a popular guy at school with plain black hair with a stoic face/personality.

Hell she's been bugging me to find it but I haven't gotten a single clue online so I thought posting it here will help. Pls help ToT