The Eyeshield 21 anime and manga series features an extensive cast of characters created by Riichiro Inagaki and Yusuke Murata. The series takes place in Tokyo, Japan, where the members of Deimon Devil Bats have the ambition to compete at the Christmas Bowl, the most important high school American football championship of the country.
The main character of the series is Sena Kobayakawa, a wimpy boy who was a gofer to avoid being bullied during his childhood; he enters Deimon High School. While he runs away from the Ha-Ha Brothers his running ability is witnessed by Yoichi Hiruma, the captain of the Deimon Devil Bats, the school's American football team. After this, Hiruma coerces Sena to join the club under the alias "Eyeshield 21" to keep him from being recruited by other teams. Sena and Hiruma along with the other member of the club, Ryokan Kurita, try to recruit new players to compete at the Christmas Bowl.
While developing the characters, Murata intended to create characters who have unique qualities and that could stand out amidst the teams they are included. He focused his work on the characters' outfits since he thought it was the thing that would be most noted during the matches. Inagaki also used real-world influence for the teams. Most reviewers have praised the characters of the series, declaring that the characters are one of the best elements of the Eyeshield 21 series as they are distinguishable.