The Saint's Magic Power is Omnipotent

is a Japanese light novel series written by Yuka Tachibana and illustrated by Yasuyuki Syuri. It began serialization online in 2016 on the user-generated novel publishing website Shōsetsuka ni Narō. It was later acquired by Fujimi Shobo, who have published six volumes since February 2017 under their Kadokawa Books imprint. A manga adaptation with art by Fujiazuki has been serialized online via Kadokawa Shoten's ComicWalker website since July 2017 and has been collected in five tankōbon volumes. Both the light novel and manga have been licensed in North America by Seven Seas Entertainment. An anime television series adaptation by Diomedéa premiered on April 6, 2021.

Plot
Sei Takanashi, an office worker, returns home late at night is then summoned to the magic world of Salutania. The ritual that summoned her—meant to produce a “Saint” who would banish the dark magic—brought two people over instead of one. The crown prince prefers the second girl over Sei. Unfazed, Sei follows her own devices and sets her sights on being a researcher at the Medicinal Flora Research Institute, an establishment known for its studies regarding herbs and potions. While indulging in her latest passion, Sei has a fateful encounter with the commander of the Third Order of Knights. But little does she know, her aptitude as a Saint will continue to exert its influence over her new life.