Ryo Ishizaki starts as captain of the perpetually unsuccessful Nankatsu Elementary School soccer team. He becomes Tsubasa Ozora's first Nankatsu friend and crucially convinces Tsubasa to stay rather than transfer to Toho Academy. Initially lacking technical skill and prone to errors, Ishizaki compensates with relentless determination and a gutsy style. His cheerful, straightforward personality often provides comic relief, though he occasionally clashes with similarly explosive teammates like Hanji Urabe. During elementary school, Ishizaki evolves from a clumsy player to a reliable defender through sheer effort. His signature "Face Block" technique involves intercepting powerful shots point-blank with his face, showcasing his willingness to sacrifice for the team. This defining move is notably used during the World Youth Cup finals, where he blocks a critical shot despite being knocked unconscious. His growth establishes him as a moral pillar for Nankatsu and the Japanese national youth teams, typically wearing jersey numbers #14 or #4. Through middle and high school, Ishizaki continues honing his defensive capabilities. Though lacking flashy dribbling or shooting skills, his tactical awareness and teamwork improve significantly via rigorous training. By his third year of middle school, he becomes a starter for Japan's U-15 team. Ascending to captain at Nankatsu High School, he leads the squad to successes including back-to-back University Championships later in his career. His dedication parallels that of Hikaru Matsuyama, another leader forged through perseverance. As a professional, Ishizaki initially follows Tsubasa to Brazil, joining São Paulo FC. He later returns to Japan, playing for Jubilo Iwata in the J-League. During international tournaments like the Madrid Olympics, his technical skills show marked improvement; he adeptly dodges opponents, contributes assists, and supports critical goals. In the "Next Dream" storyline, he advances to the European stage by signing with Lombardia, reflecting his enduring trajectory. Throughout his career, Ishizaki maintains key relationships: Yukari Nishimoto as his longtime girlfriend and Urabe as a frequent on-field rival. His unwavering loyalty to Tsubasa often uplifts the protagonist during low moments. Though occasionally error-prone, his resilience and growth from a struggling elementary captain to an Olympian underscore his character arc.