That's the Devil Bat's American Football star running back. An awesome 4.2 second 40-yard dash earned him the notoriety in the open field. But life has not always been like this for Sena, at barely 5 feet tall, he was always being bullied by his classmates. He was just a lame gopher for the school's bigger students, and worst of all, he was always being defended by a girl. Poor Sena.
How did he become the bad ass Eyeshield 21, University of Notre Dame hero with the killer tackle? You have to read the manga, or watch the (much disliked) anime. I must say that this is the funniest sports themed manga since Slam Dunk. Well, not that I have a library of sports themed manga...
You can read Eyeshield 21 in Viz's monthly Shonen Jump.