Toshifumi Iwase is Taketo Iwase's older brother, and a very strict one at that. Their parents died when Toshifumi was still in high school, and because he had to take care of Taketo by himself, being both the mother and the father, he matured very early. In front of their parents' grave, Toshifumi made a promise that he would dedicate himself into raising Taketo into a good and worthy man. Even though Toshifumi yells and scolds Taketo often, it's all out of brotherly/parental love.

His career is a policeman, and the job fits his personality very well - ever since high school, he's been extremely nitpicky about order and regulations. Toshifumi believes that he has to set a good example for his younger brother, and therefore may appear uptight at times. With a stoic appearance, one would believe that he has no fear...alas, he has a dog-phobia ^^; He thinks dogs are demons.