Kikaku-gai (E02)

Though he joined the magic academy, what awaited him was far from a normal life. Without realizing it Ard had already grown famous and he was quickly put on a pedestal by his peers. Then there was another problem within his class - the young girl, Ginny, a succubus, was being abused by Elraldo, a noble's son. Ireena then intervenes and Elraldo insults her. When Ard demands an apology, he is challenged to a duel instead. (Crunchyroll)