Karina is a police official who frequently calls on Keita and Yoko for help with cases that have a spirit, monster or magical event at its core. He has stated that he is collecting the "devil's toys" created by an ancient wizard named Sekidōsai. He has more than once gotten Keita off the hook when the latter is once again arrested for indecent exposure after angering Yoko. Karina wields an enchanted weapon he calls Angel Blade in combat. One of its signature attacks is the Holy Crush. It is later revealed that Sekidōsai is his ancestor; the two men look very much alike, except for their different hair colors. Their characters are very different as well; whereas Karina is a morally upstanding person, Sekidōsai is a pervert. However, it is later hinted at that, subconsciously, Karina may be a pervert, although definitely not to the same extent as his ancestor. He is frequently shown in a variety of fetishes, some granted by misinterpreted wishes and others the products of his subconscious desires.