Chivalry of a Failed Knight

Magic Knights are modern warriors who transform the power of their souls into weapons, and Ikki Kurogane attends a school dedicated to training them. Unlike his gifted classmates, Ikki has almost no magical ability and has been branded the "Failed Knight" and the "Worst One" because of his poor standing.

His school life changes when Stella Vermillion, a foreign princess and the school's top-ranked student, challenges him to a duel. The stakes are unusually personal: whoever loses must obey the winner for life. The match places the academy's weakest-ranked student directly against its number-one talent, giving Ikki a chance to prove that his lack of magical skill does not necessarily determine what he can accomplish in combat.