Sena Kobayakawa (小早川 瀬那, Kobayakawa Sena?) is the fictional protagonist in the manga and anime series Eyeshield 21. He is a dynamic character who, at the start of the series, avoids conflict with others for fear of being bullied; over the course of the series, Sena matures and becomes braver, and becomes willing to place himself in danger of physical harm in order to achieve his goals and help his friends and teammates. Sena is a first-year Japanese high school student and rookie American football player at the fictional Deimon High School, where he plays running back for the Deimon Devil Bats. A major element of the series' plot is the revelation of the history of the title "Eyeshield 21", which Sena is forced to use as a secret identity for much of the series.

Source: Wikipedia