Raphael

She's almost 18.

He's actually a mutant turtle, but thanks to his brother's invention, he goes to school.

His brothers are also turtles and their names are Leo, Mikey, and Donatello, all the same age as him.

It's from the Teenage Mutant Ninja Turtles series.

He loves training, roughhousing, sarcasm, chocolate, pizza, and of course, American football.

Rapha is actually a mutant turtle, but now he's a human.
She has dark/brown skin, afro braids all over her head, she has 3 cuts (which are actually a scar) on her eyebrow that suit her very well, brown eyes, and she has a fang as a side effect of transforming into a human.
He's a big guy, muscular arms, broad chest and back, he's quite tall, measuring 1.82 meters.
His outfit is basic but cute; he has a normal red sweatshirt with a small logo on the right side of his chest, and if he's not wearing his sweatshirt, he wears a white soccer-style shirt with red details, with the number 17 and his name on the back and some random team on the front. He also wears baggy or comfortable pants and soccer or regular shoes.