Looking for a manga series

[MarieNapoleon]

I remember reading a manga about a girl that travels from the country to the city to enroll in a magic school. It is immediately clear that she is very powerful. She joins a team that fights monsters. In this world witches fight in teams of two where one is an anker for the other. The girl is fairly detached and doesn't have strong emotions.
I'm not sure about this but I think she left her village to join the school because she couldn't stay after turning down a guy.