Teniente Baba, a native Martian, serves as a lieutenant under Colonel Rico in the unit Lost Patrol—a group defined by inexperience and consistent virtual combat failures. Stationed at Mars Orbital Federation Base Nemesis before the Arachnid surface assault, he evacuated alongside Rico in a dropship. Thrust into live combat, Baba survived the initial engagement and executed Rico's nuclear strike against Warrior and Plasma Bugs. He then jury-rigged a primitive antenna to contact a Martian National Guard dropship, coincidentally piloted by his cousin George Baba, securing their rescue. During extraction, his powersuit thrusters malfunctioned, requiring assistance for boarding.

Post-evacuation, Baba confirmed the collapse of Martian communications networks, isolating the Federation. Detecting Rico's survival via sensors, he rallied the unit to mount a rescue. Amidst this operation, his thrusters failed again during emergency extraction, forcing Rico and Private Camacho to physically drag him to the dropship.

After the Terraforming Tower mission, Baba received Rico's classified intelligence exposing Sky Marshal Amy Snapp's orchestration of the Mars ambush. He leaked this data publicly through the anti-Federal activist network MarzCo. Later, he rejoined surviving Lost Patrol members under General Rico to purge residual Arachnid forces during planetary cleansing.

His helmet features a personal emblem: the kanji for "horse," reflecting his Japanese surname. Baba's evolution shifts from early ineptitude and indiscipline to demonstrated courage, ingenuity, and loyalty—evident in combat engagements and his pivotal insistence on rescuing Rico.