Mamiya is a light-skinned young man of average height and build. He has medium brown hair gathered in slightly messy, soft spikes. Like the other members of his unit, in his trion body he wears dark pants, a lighter jacket with a high collar, and boots of the same color, as well as dark-rimmed goggles with square, protruding lenses.
As the leader of a B-rank unit, Mamiya should be more skilled than a C-rank agent and have a modicum of leadership and strategic abilities. His unit's foremost tactic is a combined attack which sees the three Shooters focusing their Full AttackHound on a single target. This technique, called Hound Storm, was extolled by Ken Satori as a very powerful attack. However, the whole unit was easily defeated by the combined might of Chika and Yūma without managing to put up any form of resistance.