Sōma Saitō will voice protagonist William James Moriarty, who was adopted into the Moriarty family after he caught the eye of the Moriarty scion Albert.
In the manga, he is an orphan who assumes the name William James Moriarty when he and his younger brother are adopted into the Moriarty family.
Takuya Satō plays Albert James Moriarty, the eldest among the Moriarty brothers.
Chiaki Kobayashi plays Louis James Moriarty, William’s biological younger brother.