Lieutenant Toshi Baba is a native of Mars who serves as a platoon leader in the Mobile Infantry under Colonel Johnny Rico, assigned to the Mars Orbital Federation Base Nemesis. He is a member of the so-called Lost Patrol, a group of inexperienced troopers stationed on the space station orbiting Mars. Initially, Baba is depicted as uncertain and flustered, struggling to inspire confidence in his squad and often appearing overwhelmed by the demands of leadership. As the Arachnid invasion of Mars unfolds, he is forced to adapt quickly, growing into his role and developing the decisiveness needed to command under fire. Baba shares a personal connection with his cousin George Baba, a pilot in the Martian National Guard. Throughout the story, his primary motivation evolves from simple survival to taking responsibility for his subordinates, and he ultimately demonstrates the ability to lead effectively in combat. His notable abilities are those of a standard infantry officer rather than any specialized skill, relying on training and determination rather than exceptional physical prowess.