Strike the Blood

Kojou Akatsuki was a normal high school student before suddenly becoming the Fourth Primogenitor, a title marking him as the most powerful vampire in existence, though he has no memory of how this occurred. Yukina Himeragi, a middle schooler and Attack Mage, is assigned to monitor him and intervene if he becomes a threat. She is placed in a challenging situation due to his powers, which intensify when he experiences arousal. The two are located on an artificial island that houses various individuals with supernatural abilities, each having their own interest in the Fourth Primogenitor.