"Inazuma Eleven" centers around Mamoru Endou, a passionate and determined goalkeeper who leads his school's soccer team, Raimon Junior High. The series begins with Raimon's soccer club on the brink of dissolution due to a lack of members and poor performance. Mamoru, inspired by his grandfather's legacy as a legendary goalkeeper, strives to revive the team and restore its former glory. His journey intertwines with the discovery of a mysterious notebook left by his grandfather, which contains advanced soccer techniques and hints at a larger, hidden world of competitive soccer.

As Mamoru recruits new players, the team faces increasingly formidable opponents, including rival schools and shadowy organizations like the Aliea Academy, which seeks to dominate soccer through unethical means. The narrative explores themes of teamwork, perseverance, and the spirit of competition, as Mamoru and his teammates develop their skills and form unbreakable bonds. Key characters include Shuuya Gouenji, a talented forward with a troubled past; Kazemaru Ichirouta, a skilled midfielder and Mamoru's close friend; and Kidou Yuuto, a strategic genius who initially opposes Raimon but later becomes a crucial ally.

The plot escalates as Raimon uncovers the truth behind Aliea Academy's sinister plans, involving the use of advanced technology and manipulation to control soccer worldwide. The team must confront not only physical challenges but also moral dilemmas, as they strive to uphold the integrity of the sport. The series blends intense soccer matches with elements of science fiction, as players unlock special abilities known as "hissatsu techniques," which add a fantastical dimension to the gameplay.

Throughout the series, Mamoru's leadership and unwavering belief in his team inspire those around him, leading to dramatic victories and personal growth for each character. The narrative culminates in a high-stakes tournament where Raimon faces off against Aliea Academy's elite teams, testing their resolve and unity. The story emphasizes the importance of friendship, trust, and the pursuit of one's dreams, making it a compelling tale of sportsmanship and determination.