into a villain. Ohkawa applied to Kamui and Fuma ideas she had during middle school, such as a person's dual nature and how people can be considered good or evil. Kamui meets Tokyo Babylon protagonist Subaru Sumeragi, whose rivalry with Seishiro Sakurazuka parallels Kamui's rivalry with Fuma. Clamp referred to Kamui and Subaru as siblings; Kamui is supposed to learn from Subaru's final fight with Seishiro, so his final fight against Fuma does not have the same tragic conclusion. Fuma's transformation from a supporting character to the main villain was difficult for Clamp, since his sister Kotori Monou would die during this transformation. They introduced Fuma and Kotori over eight volumes due to the storyline's violence, and even readers who disliked Kotori expressed sorrow at her death. Since the series has a number of talkative characters, Fuma would be more of a silent teenager; most of his dialogue involves Kamui. In his early appearances Fuma was one of Clamp's worst silent characters according to the authors themselves as he barely had dialogue only when involving his sister and Kamui, making them to look forward to his transformation into a villain. Fuma murdering his sister was one of Clamp's most gruesome scenes. They persisted, despite editorial opposition, because they had already foreseen it in one of Kamui's dreams. Fuma's murder of Daisuke Saiki was also opposed because of its violence, but the editors decided to rely on reader reaction. Clamp artist Mokona felt that Fuma was the hardest character to draw, since they had to make him resemble other characters such as Kusanagi Shiyū when Yuzuriha Nekoi sees him. Clamp avoided the idea of Seiichiro Aoki (a character based on their editor) meeting Fuma, since they would be forced to make Fuma androgynous. Artist Satsuki Igarashi found drawing the Dragons of Heaven and Earth at the same time difficult because of their individual clothing, which made her wish that they wore identical outfits. In the Japanese X film, Fuma is voiced by Ken Narita in Japanese and Adam Henderson in English; the character is voiced by Junichi Suwabe in the television series. Suwabe found voicing Fuma difficult due to his dual personality: one kind, and the other cold-hearted. He also noted that the X manga was very popular in Japan, and he wanted to meet audience expectations. Suwabe befriended Kamui's actor, Kenichi Suzumura, while recording the anime. Crispin Freeman replaced Suwabe