Kei serves as the Commissioner of the Police Department and is Satoshi's adoptive father, appearing in both the manga and anime. Known for his ruthlessness, particularly towards Satoshi, he harbors a deep obsession with the Hikari artworks, which partly motivated him to adopt Satoshi, the last descendant of the Hikari family. He assigned Satoshi to return to middle school to spy on Daisuke Niwa and appointed him as Chief Commander of Police, responsible for capturing Dark, despite Satoshi often interfering with these plans. In the anime, Kei discovered the voodoo doll known as Mio Hio and sent her to the same school as Satoshi to manipulate Daisuke into wearing a magical pendant in exchange for giving her a real human body. It was revealed that Kei had enlisted Krad to assist him in awakening the Black Wings by searching for an ax-like object passed down through the Hikari family, later found sealed inside the Hikari Throne, located in Satoshi’s room. Although cold, there are moments when Kei shows a softer side toward Satoshi, such as when he complimented Satoshi while he was painting, indicating he cared for him before his presumed death. It remains unclear if Kei actually died at the end of the anime after Mio tried to stop him from activating the Black Wings.
Some speculate that Kei may have had past connections with Rio Hikari, Satoshi's biological mother.
