Eyeshield 21 is a Japanese manga series written by Riichiro Inagaki and illustrated by Yusuke Murata. The series tells the story of Sena Kobayakawa, an introverted boy who joins an American football club as a secretary, but after being coerced by quarterback Yoichi Hiruma, becomes the team's running back, wearing jersey number 21 and an eyeshield to conceal his identity. Inagaki chose American football as a central subject of Eyeshield 21 after realizing that it fit perfectly with his idea for the series.