Katsuma is a young boy with brown eyes, curly, light brown hair, and a small patch of freckles in the middle of his face. He wears a pair of blue overalls with dark blue straps over a white T-shirt, accompanied by light blue sandals. He also carries a small, yellow messenger bag that has a pin of the Pro Hero Edgeshot's face fastened onto the strap. Additionally, Katsuma sports a bracelet with a floral charm on his left arm like his sister, along with a large sun hat which has blue stripes.