Rio Mataro is a central character in the anime series. Known for his sharp intellect and strategic mind, Rio often finds himself in the thick of the action. His resourcefulness and quick thinking make him a key player in overcoming the challenges faced by his group. Despite his serious demeanor, he cares deeply for his friends and is willing to take risks to protect them. As the series progresses, Rio's character development adds depth to the storyline, revealing his personal struggles and growth.