Owari no Seraph

Upon the arrival of a mystery illness that kills everyone over the age of 13, hitherto undiscovered, power-hungry vampires emerge to conquer society in exchange for blood donations with the promise of safeguarding the survivors. Yuuichirou and Mikaela Hyakuya, two young boys who are kidnapped from an orphanage, are among the surviving, along with other kids who they regard as family. Mikaela devises a rebellious escape scheme that is ultimately doomed to failure because she is unhappy with how the vampires treat her as though she is merely farm animals. Yuuichirou is the sole survivor who makes it to the other side and is discovered by the Moon Demon Company, a military squad tasked with eradicating vampires in Japan. Yuuichirou is resolved to exact revenge on the monsters that killed his family many years later as a soldier of the Japanese Imperial Demon Army, but at what cost? Owari no Seraph is a post-apocalyptic supernatural shounen anime that centers on a young man seeking vengeance as he struggles against overwhelming odds for friendship and loyalty.