I didn't read all of the posts on here, but I just wanted to say, for anyone on the fence about whether or not to visit Japan....DO IT!!!
I haven't been on any ABD trips before, but I saw the post that they're going to Japan and that is very exciting.
I've visited Japan 5 times and I've taken a few friends from here in Florida with me and also my fiancee from the Philippines. Everyone immediately said they want to go back in a heartbeat if they could.
It's really difficult to really describe how different it is, but refreshing.
Things are very organized, and very convenient. People take whatever job they have there very seriously, and put their maximum effort in. You'll notice customer service levels that we can only dream about in other countries, partly because it's expected and partly because the culture is about doing your best, no matter if they have a lower tier job or not.
They also like to help foreigners who get lost, even if they can't speak the language very well, you'll often find people willing to help.
If you get the chance to go to a convenience store, try the food. I'm serious!! Unlike the U.S. the food offered there VERY high quality and very good, it's especially great if you're on a budget.
Also, many restaurants have either photos of the menu items or outside they will have examples of the items, so you can just point to what you want.
Of course, it's good to know some words in Japanese as they'll usually be highly appreciative of the effort.
Japan is an amazing mix of well preserved historical sites, incredible new technology, and somehow is able to balance it all.