Playing American/Gridiron Football in Japan

Good afternoon

I'm considering taking a year abroad to complete my masters degree, and picking up my high school pastime in another country sounds like a wonderful opportunity. at my current size, I think that I would be a division 3 or 4 player in the KCFAL. This leaves me with a couple of questions:

1. What kind of eligibility requirements are there for playing collegiate/university sports in Japan? I know in the XLeague, there is a limit on foreign players. does this exist at the collegiate level?

1. Are there other major leagues in other regions that offer football at a collegiate level?
   While I was a "all Conference" player in high school, i am quite small for standard players in my position. I am nowhere near good enough to play at a high level. I would love to enjoy the game i love and meet new people!

Thanks for your time!