Suomi Käyhäinen is a main character in Girls' Frontline, a mobile strategy game and anime adaptation. She is the anthropomorphized form of the Suomi KP/-31 submachine gun, depicted as a T-Doll (Tactical Doll). Suomi is portrayed as a kind, quiet, and reliable member of the squad, often acting as a mediator among her peers. Her role in the series involves frontline combat, supporting her teammates, and exemplifying steadfast loyalty and bravery under fire.