Mamoru Izawa, known as Paul Diamond in occidental adaptations, is a Japanese midfielder valued for his versatility and tactical intelligence. Starting at Shutetsu Elementary School, he later transfers to Nankatsu, becoming a core squad member alongside Tsubasa Ozora. As Nankatsu's shadow playmaker, typically wearing jersey number 8, his technical dribbling and playmaking skills stand out. He forms the "Shutetsu Trio" with Teppei Kisugi and Hajime Taki, utilizing coordinated one-two plays to create scoring chances. His notable heading ability dominates aerial duels. Primarily a midfielder, he adapts effectively to defensive roles. This utility makes him a valuable substitute for Japan's national youth teams across U-15, U-19, and U-22 levels. During the J-Boys Challenge, Izawa participates in the France-Japan match but sustains a shin injury from Napoleon, leading to substitution by Jun Misugi. His resilience continues in the Road to 2002 arc as he joins Yokohama F. Marinos professionally. For the U-22 Japan team, he replaces the injured Hiroshi Jito against Denmark, enabling a tactical defensive shift. His flexibility further benefits Japan during Asian World Cup qualifiers. Izawa's appearance evolves: elementary school (155 cm, 45 kg) features a hot-headed demeanor; middle school (169 cm, 56 kg) shows a calmer presence and leadership; high school (177 cm, 62 kg); professional (178 cm, 66 kg). His distinctive shoulder-length hair remains consistent. His development traces a path from a skilled, temperamental youth to a dependable, multifaceted player influencing matches through defensive solidity, playmaking, and aerial prowess.