D.Gray-man is an anime series based on the manga by Katsura Hoshino. It follows Allen Walker, an exorcist with a cursed eye and a powerful weaponized arm, as he battles Akuma and the Millennium Earl. Set in an alternate 19th century, the story explores themes of salvation, sacrifice, and the eternal struggle between good and evil. The series is known for its dark, gothic atmosphere and compelling character development.