Kufa Vampir, a young assassin from the White Night guild, is sent to tutor Melida Angel, heiress of a noble house of paladins. His secret orders: kill her if she cannot manifest mana. In Flandore, the last city-state, humanity survives behind glass domes surrounded by lycanthropes, and noble bloodlines are the only source of magical power, so Melida's failure to awaken hers at thirteen has made her a target of ridicule. When Kufa watches her fight a lycanthrope bare-handed, he defies his orders and shares his own mana with her instead.