Hakugai Fukutsu no Blade Maker (Volume)

is the first volume of the Hakugai Fukutsu no Blade Maker light novel series, written by Ibukiyo Amoh and Illustrated by Hinata Momo. It was released under the Dengeki Bunko Imprint in November 2015.

Synopsis
A «Saint Renshi» girl who exposes herself naked in a flameless smithy. Insert the holy sword of the hero (for) into that XX !? The holy sword that destroys the human enemy "Makina" -it is sanctified using the body of the "Holy Renshi" as a fire pot. In other words, everyone needs to expose their bare skin during the sacred training ... On the first day of transfer to the Holy Ren School, the fallen Holy Renshi, Judas, rushes into the "Holy Renchu" smithy with his honor student, Ildane. Judas decides to duel with her, who is furious when she sees her "inserting" her armor. But he had a secret. An incompetent saint who can't even train a knife properly. Its true identity is the strongest warrior who has mastered overwhelming sword skills and various magic.

(source: Dengeki Bunko Official Website - Translated)