Seraph of the End: Vampire Reign

An unknown virus devastates humanity, leaving many children younger than thirteen at the mercy of vampires who enslave them.

Yuuichirou Hyakuya grows up within this new order with a simple ambition: become strong enough to kill every vampire. Seraph of the End: Vampire Reign follows Yuichiro in a post-catastrophe world where humanity has already suffered near-total collapse and vampires hold overwhelming power over its youngest survivors. His determination places him at the center of a struggle defined by revenge, survival, and the conflict between the remaining humans and the supernatural forces that now dominate them.