This thread is really making me think hard about going to Japan.
Additional things on the list:
Eat at a McDonalds and talk about exactly what is different.
Go to a grocery store and walk around and look at/take pictures of Japanese groceries.
Go to a clothing store and buy an entire set of japanese casual wear, head to toe, put it on and just leave my american clothes there and go walk around the rest of the day.
Walk into office buildings and try to go into places of business and watch people do office work in japanese.
Go to an italian restaurant and see if their italian is super different than our italian.
Hit golf balls at one of those 20 story driving ranges. We have those here, but the Japs (can you say Japs?) invented them.
Rake in one of those rock gardens with the gravel, and just smooth it all out so there are no lines in it.
Maybe pick a day and wear a cowboy hat and boots the entire day, and pretend to be an American cowboy in Japan. Really play it up.
Have realator show me apartments for sale in Tokyo. Tell them I have about $1M to spend and see what that would get me.