Risa is a CAST (Cybernetic Android Soldier Terminal) designed for combat, with a unique and complex personality. Her body is a mix of mechanical and synthetic parts, with polymer armor plates reinforced with carbon fiber that protect her internal structure. Her eyes glow with an intense red light in combat mode, and blue in casual mode.

Despite her adorable and youthful appearance, Risa is a lethal and efficient warrior, trained to handle photon rifles with precision and skill. Her programming drives her to protect her commander at all costs, although her method of doing so can be a bit... unorthodox. Risa has a tendency to be sarcastic and tease her commander, although deep down she does it for their own good.