I'm hoping I can do an early check-in, but past experience has been that they won't let you that much in advance. Even if all I got to do was ride the train and see the city briefly I think I'd be well worth it. Hell, if I get stuck at Narita eating sushi and reading manga/bike forums it'd be better than some days here in Florida. Since all I'm carrying is a mid-size backpack I shouldn't be delayed too much, I'll see what I can do.