Maou Reijou no Kyouiku-gakari: Yuusha Gakuin wo Tsuihou sareta Heimin Kyoushi wa Maou no Musume-tachi no Katei Kyoushi to Naru

After being fired from the Hero Academy, Frey was offered a new job by a mysterious maid. The job was to be the tutor for the Demon Lord's five daughters! (Source: Comic Polca, translated)