The D.Gray-man anime and manga series features a cast of characters created by Katsura Hoshino. The series is set at the end of a fictional 19th century during which the Black Order searches for Exorcists, the "Apostles of God" chosen to wield a divine substance called Innocence. They are the only ones who can destroy Akuma, weapons created by the Millennium Earl from souls of the deceased when humans curse God for the loss of loved ones, and stop the Earl's plan to destroy humanity.
The series' main character is Allen Walker, a young Exorcist who trained under Exorcist General Cross Marian and is sent to officially join the Black Order. Early in the series, he is sent on missions with fellow Exorcists. He meets Yu Kanda, a cold and mysterious swordsman looking for a certain person from his past; the friendly Lenalee Lee, who has been an Exorcist her entire life; and Lavi, the cheerful and energetic future Bookman, chronicler of the secret history of the world. They travel the globe, retrieving the pieces of Innocence scattered during the Great Flood and recruiting new Exorcists while fighting the Earl and his Akuma. However, the Black Order soon learns the Earl has help in the form of the Clan of Noah, a group of thirteen super-humans who can destroy Innocence and claim to be the true "Apostles of God". Both groups quickly begin searching for the Great Heart, the most powerful Innocence that can strengthen or destroy all the others, to bring an end to the war.
Many of the series' characters are taken from Hoshino's previous one-shots, both published and unpublished. She also modeled characters on her friends and well-known people. Designing and illustrating most characters was often difficult due to their beauty as well as their personalities. Critical reception to these characters has been positive, with writers praising most of the cast members as well as their development. The antagonists received a similar response. However, initial chapters of the manga, or episodes of the anime, attracted some criticism as a result of some of the characters feeling generic. Critics praised the voice actors for both the Japanese series and the English dub.