They re-broadcast it here in Japan, mainly for the American community (like myself) who watch it. Japan actually does have its own football league and some high schools and universities have teams, but none are well-known at all. They don't air the pro league's games on TV. I only knew about it from seeing scores on a newspaper's website. I didn't watch it this year because I already saw the score and being a Minnesota Vikings fan, I really had no desire whatsoever to watch my mortal enemies claim the title. Just reading the US sports magazine websites this season, I had to put up with sportswriters going stupid in their love for the Packers and hatred of the Vikings this year already.
So having a league and all, there's a bit of a following for the sport here in Japan, but rugby is definitely more popular here too. I do know a few Japanese people who follow the NFL, but there is a big emphasis on the FEW. Though no other sport here besides sumo (if only for the tradition) can hold a candle to baseball's popularity here. Japan's league's spring training is all over the sports headlines. I'm a big fan of baseball in the US and I actually want to follow the Japan pro baseball league more closely here.