As the resident anime/manga fan here, I would highly recommend not watching the anime, and switching over to the original manga version of it. By anime standards, ES21 isn't very good, while the manga is excellent. Artistically, especially.
It's one of my favorites.
To summarize, Sena (the main guy) is fast, he's the running back, he gets recruited to the small Football club at Deimon high school, they recruit more guys, they're trying to get to the Christmas Bowl through the fall tournament. It's a good read.