When designing the characters, Hoshino first imagines their lives even though some parts might not be featured in the story. Their personalities are then written down along with their habits or eating preferences. She has admitted she does not have written details about a number of "D.Gray-man" characters. Hoshino chose the title "D.Gray-man" for its multiple meanings, most referring to the state of Allen and the other main characters. The Akumas were inspired by 1973 film, "The Exorcist" which Hoshino admitted scared her when watching it. In Timcanpy's case, his design is based on the silver accessory brand Timcanpi. The character Bak Chan was created with the help of Kaya Kizaki, who wrote the "D.Gray-man Reverse" novels. Hoshino has revealed that she got most of her ideas for the series while asleep in the bath for six hours.