Muryoku Seijo to Munou Oujo: Maryoku Zero de Shoukan sareta Seijo no Isekai Kyuukokuki

In this thrilling yuri fantasy, Nana's just out of college, trying to make her way on a series of part-time jobs, when she finds herself whisked away from her bedroom into a parallel world of magic! To her shock, she's told that she is the great saintess who will bring peace and prosperity to the whole country. Except for one tiny problem—she soon discovers she has absolutely zero magical power—none! To make matters worse, the princess she's been summoned to serve with can't cast even a single spell. A saintess with no magic power, and a princess who can't use her own—a pair of failures, doomed to become a laughingstock...or a partnership that might deepen into something more?

(Source: Kodansha USA)