Alga is a robotic member of the Escape Shop Extractors team. He specializes in providing technical and tactical support during operations to smuggle individuals between walled city clusters. His mechanical body hides internal storage compartments housing various tools and weaponry, including missiles and laser guns, which he deploys as needed during missions. Alga emits a distinctive odor reminiscent of an old man.

Outside extraction missions, Alga functions as a waiter robot at Cafe Vostok, the team's base of operations. Within the team dynamic, he maintains a focused and utilitarian approach. He directly contributes to mission success through technological expertise and resource provision, avoiding frontline combat and extensive interpersonal interactions.

His characterization remains consistent in these defined support roles during both extraction operations and civilian cover activities at the cafe. No concrete information exists regarding Alga's origins, creation, personal history, or significant character development across the series, the subsequent film *Bloody Escape: Jigoku no Tōsō Geki*, or other related media.