Masaru Mahha is the main protagonist of Crush Gear Nitro. He is enthusiastic about Crush Gear and enjoys Gear Fighting very much. His Crush Gear is Mach Justice which is upgraded to Mach Justice Sonic later in the series. He also uses Mach Victory during the Crush Gear World Championship.
Masaru is shown to have green eyes and dark blue hair. His usual outfit consists of a short sleeved salmon-colored jacket with yellow hem and buttons, a turquoise shirt with white hemline and a pair of red wristbands. He also has a yellow cargo shorts with salmon-colored hem, yellow socks and a pair of orange and white sneakers. From episode 3 onwards, he had the Crush Kid goggles tied around his left upper arm.