Seemingly always calm and composed, never showing much emotion, Satoshi Hiwatari is a very distant, cold, and silent character, though these qualities never seem to affect how close he keeps to Daisuke Niwa. He is extremely intelligent, having graduated from high school at eight and graduated from Lagoon University at thirteen. However, he attends Daisuke's Junior High School, saying to Daisuke that he does so in an attempt to have a normal life.
He is the police commander in charge of capturing Dark, and due to his family legacy, he is almost obsessive in his attempts to capture the phantom thief. He is the sole living member of the Hikari family, whose artwork is almost always Dark's targets for stealing. He was adopted by a 26-year-old police officer whose family name is Hiwatari, so his name was changed to reflect his adoption. During the course of the story, he begins to care more about Daisuke's safety. It appears that Daisuke is the trigger for Satoshi's other personality, Krad, to appear. Satoshi opposes Krad taking control of his body greatly, and has taken on an uncaring personality to 'seal his heart,' and thus, Krad. Krad is Dark's "evil twin", or opposite, a homicidal blond whose only motivation seems to be getting rid of Dark, Daisuke, and anyone else that comes between him and Satoshi
His (adopted) father is the Chief of Police, and they are investigating Dark. Satoshi is also the Commander in the investigation of catching Dark. His original name is Hikari, and his family have been at war with the Niwa family for centuries. The only person he intentionally seeks out is Daisuke.
He wears glasses even though he doesn't need them. His eyesight is fine, not to mention his observational skills are impressive. He records his observations in a small black notebook.
His true last name is Hikari, whose meaning is debatable. Although in the Japanese manga it is written as Hi-kari[氷狩], in the anime, there have been implications of it being synonymous to 'light'[光]. Most translations of the kanji for Hikari translate the name as 'ice hunter.'