male protagonist Allen Walker. The characters Lavi and Yu Kanda were carried over from two unpublished titles. In making the demons known as "Akuma" from D.Gray-man, Hoshino was inspired by the 1973 film, The Exorcist, even though she was afraid of the movie. By the release of the series' 13th collected volume, Hoshino revealed the material she uses when working, which included a PlayStation Portable, an iPod and a glove her mother made for her. She uses unnamed famous scientists, Aleister Crowley and Yūsuke Santamaria as models for several of her characters. Characters are also based on her editor and the Tim Campi Design silver accessory brand. Hoshino collaborated with Kata Kizaki, the author of the novel adaptations, to create the character Bak Chan. The role of Miranda Lotto changed, and was ultimately lengthened, after Hoshino realized the similarities the two shared. Hoshino comically comments that Allen's hair has become very similar to the Super Saiyan, a transformation from Dragon Ball, in which the character's hair becomes spiky. Towards the beginning of D.Gray-mans publication, Hoshino stated that Allen, Kanda, and Cross Marian are the hardest characters to draw while the Millennium Earl and Hevlaska are the easiest. Hoshino commented that most of her ideas for the series come after falling asleep in the bath for six hours. An exception occurs in the plot for second volume of the series, which is based on a Noh play called Koi no Omoni. As she works, she enjoys listening to Final Fantasy soundtracks, Dragon Ball CDs, the bands Porno Graffitti, L'Arc-en-Ciel, and jazz music. Hoshino feels grateful to the editors assisting her, owing her D.Gray-mans success to them. She has also thanked her mother in some volumes of the series. The story arc involving Alma Karma proved Hoshino to difficult due to the fact it featured several characters. As a result, this arc set up Allen's departure from the Black Order to feature less characters per chapter. She has also commented the series' main theme was "tragedy" but still aims to make it fun. Additionally, once she has finished D.Gray-man, Hoshino wishes to make a more lighthearted series. In order to gather research for the series, Hoshino once visited New York as she believes the city left a deep influence in her works. She also visited graveyards since she never had resources for the series. The ground zero of the World Trade Center