In Tokyo, a weak, unassertive boy named Sena Kobayakawa enters the high school of his choice, Deimon Private Senior High School. Sena's only remarkable physical abilities are his running speed and agility, which are noted by the school's American football team captain Yoichi Hiruma. Hiruma forces Sena to join the Deimon Devil Bats football team as its running back. To protect his identity from other teams who want to recruit him, Sena is forced to publicly assume the role of the team secretary and enter the field under the pseudonym of "Eyeshield 21" wearing a helmet with an eyeshield to hide his features.

Miyu Irinoas Sena Kobayakawa / Eyeshield 21 (voice)
Atsushi Tamuraas Yoichi Hiruma
Aya Hiranoas Mamori Anezaki
Mamoru Miyanoas Haruto Sakuraba
Kappei Yamaguchias Raimon Tarou
Daisuke Hirakawaas Hayato Akaba
Daisuke Onoas Kengo Mizumachi
DJ Taroas Devil Bat
Eiji Takemotoas Niinobu Kasamatsu
Hiroshi Shimozakias Osamu Kobanzame
Kow Otani