Owari no Seraph, also known as Seraph of the End, is a post-apocalyptic anime series set in a world where a virus has wiped out most of humanity, leaving only children and vampires. The story follows Yuichiro Hyakuya, a young boy determined to avenge the deaths of his family by fighting against the vampires who have taken over the world. The series explores themes of friendship, loyalty, and the struggle for survival.