Mamoru Endou is the main protagonist of the Inazuma Eleven anime and manga series. He is a student at Raimon Junior High and serves as the goalkeeper and captain of the school's soccer team, later also taking on the role of libero. His passion for soccer is boundless, and he is defined by an unwavering determination and an optimistic, never-give-up attitude. He consistently puts the well-being of his teammates before his own and draws strength from encouraging those around him, making him a natural and inspirational leader.

Endou's primary motivation stems from his deep admiration for his grandfather, Daisuke Endou, a legendary goalkeeper. He studies the technique notebooks his grandfather left behind, striving to honor that legacy and become a truly great goalkeeper himself. His love for the sport is so intense that he is often called a soccer fanatic, and his energetic personality helps him rally others to his cause, whether it is rebuilding the nearly defunct Raimon soccer club or forming the national team, Inazuma Japan.

Throughout the story, Endou's role evolves from a determined but isolated goalkeeper into a seasoned captain and, in later years, a mentor. In the original series, he leads Raimon through the Football Frontier tournament, then faces an alien threat in the form of Alius Academy, and finally captains Inazuma Japan in the international Football Frontier International competition. Ten years later, in Inazuma Eleven GO, he returns as the coach of Raimon, guiding a new generation of players and later coaching Chrono Storm. His development is marked by his ability to inspire loyalty, his growth in handling pressure, and his gradual mastery of more advanced techniques.

Key relationships include his close bond with striker Shuya Gouenji, whose arrival gave Raimon its first real offensive power, and his partnership with midfielder Yuuto Kidou, a strategic mind who becomes a trusted ally. He also forms strong connections with teammates like Heigorou Kabeyama, Ichirouta Domon, and Ichinose Kazuya, as well as later players such as Toramaru Utsunomiya. His grandfather's legacy remains a constant thread, influencing his techniques and philosophy.

Notable abilities center on his remarkable goalkeeping skills. He develops a wide array of hissatsu techniques, starting with God Hand, a powerful save that conjures a giant hand, and later progresses to Majin The Hand, Ijigen The Hand, and God Catch, among others. He also learns offensive team techniques like Inazuma Break and Jet Stream, which he uses in coordination with his teammates. His refusal to give up, even when faced with seemingly impossible shots, is arguably his greatest strength, as it pushes him to constantly improve and rally his team to victory.