So there are 6 (or 7) legendary children. They need to protect the humanity, but one of them is demon (they don't know who it is).
So a girl (the main character) and a boy don't like each other, they are walking home from school and a legendary kid appears and saves them from a weak demon. Then he says he hates that the boy is useless and that he should die and then swears to protect the protagonist.
After that, they all go to a shrine and a priest tells them they're legendary kids and can have powers. One of them starts to punch the idols because he wants power, then you find out the girl is the demon.
The girl has hair that's up at the back of her head. One of the guys has light hair (I don't know what color) and the other guy has black hair and black eyes. This is a romance manga.
Please help me find this manga. Thanks 😊