In Eyeshield 21, Deimon wins the game against Oujou that gets them into the Christmas Bowl but they're never shown actually playing in the Christmas Bowl.
Is there a manga that went with this anime that shows the time between beating Oujou and playing professional football or are we just to assume that they won?
There is in fact an Eyeshield 21 manga, which continues the story further than the anime. The anime ends on chapter 239 of the manga, while the manga continues to chapter 333. The manga doesn't go as far as professional football, but the last chapter does end with a similar scenario at the college level.
