Ishizaki Ryou is Tsubasa Ozora's best friend since the story's very beginning. He lives in the city of Nankatsu, Shizuoka and is introduced as the captain of the until then very unsucessful Nankatsu elementary soccer team.

Though Ishizaki's soccer techniques are far from Tsubasa's level, his strong will and relentless personality has won himself a position in the national team. A demonstration of this is shown during World Youth Cup Finals when Ishizaki was knocked out-cold by blocking an extremely powerful shot at point blank range with his speciality, the face block defense.