Yukina Himeragi

Yukina Himeragi is the female protagonist of the series. She is an attack mage, or in the Lion King Organization, a Sword Shaman, who is sent by the Lion King Organization to observe the Fourth Primogenitor, Kojou Akatsuki. As she's appointed to observe him, she became a middle-school student studying in Saikai Academy who follows him everywhere and is also ordered to kill him if he becomes too powerful and insane to control himself.