Leo, a cheapskate boy who likes money more than anything, because of an unexpected circumstances, had his body swapped with a beautiful girl named Leona. Leona was a young marchioness who lost her place in the noble society because of a false accusation. Then, unwilling to go to the academy filled with those nobles, she tried to escape by using sorcery. Promised with an attractive sum of reward, Leo decided to go to the academy in place of Leona. Leo was someone who, if appeared in the academy, would be chased away immediately. However, now with his (her) peerless beauty and peculiar values, Leo was being mistaken as a "Pure Maiden" by his (her) surroundings. The marquis couple, an imperial princess, and even the first imperial prince all began to have an interest? This is the story of Leonora Von Halkenberg, who came to be called as the "Altruistic Saintess."