A hot-blooded detective, Kataoka has been Matsui's subordinate partner for half a year. He is a modern young man who follows Matsui around while mumbling complaints about the 2nd Unit, Gotoh and others, saying, "Why on earth do detectives have to work for a person in the Security Bureau?" Despite having doubts about the whole investigation, he continues to pursue Ei'ichi Hoba with Matsui.