Muryoku Seijo to Munou Oujo

One day, listless part-timer Tamura Nana was summoned out of her room and into another world, after which her summoners declared her a saint and asked her to save their world. However, though she was hailed as a saint, it turned out that Nana possessed no magical power at all! To make matters worse, she was chosen as a partner by a princess who can't use magic......