Riko is a young, slim girl with long dark hair braided in the back. She is often seen wearing a light hairband and her school uniform. She is an outspoken and feisty individual who initially embraces her role as the Star Plasma Vessel but ultimately desires to live her life with her caretaker, Misato, and friends. She values personal relationships, becoming easily flustered when it comes to people she cares about. Her decision reflects her longing for companionship and a sense of belonging.