Well, I recently visited the Japanese home. After all my preparations I still made a few mistakes, but I think it went well enough. I was wearing a huge backpack when I entered and it was very difficult to move around in the genkan (entrance). So I set my shoes down facing the wrong way, and the mother moved them.
Apparently the parents were a little nervous about meeting me. They used to speak English quite well, but had forgotten nearly everything over the years. As soon as dinner began, the father cracked open a bottle of sake and insisted that I join him in finishing it. By the end of the meal, we were both feeling pretty loose. I tried to speak as much Japanese as I could, but it's been a long time since I spoke Japanese regularily, so my friend did a lot of translating. The mother cooked a very nice Japanese meal, but unfortunately, when I travel I usually don't get very hungry. I thought I ate quite a lot, but they kept trying to get me to eat more, probably expecting that all Americans eat a lot. After dinner I gave them their gifts because they opted to do it then, rather than before dinner. They seemed to like their gifts, local items from the Northwest.
After dinner I took a shower and bath, as I knew it was expected before going to bed. I don't usually take a bath, but they'd already run the water for me, so I figured I'd better. I showered, then bathed, and although my friend told me that I could drain the water, I didn't, because I'd heard that you're not supposed to.
I slept in the tatami room we'd eaten dinner in that had now been converted into a bedroom with a futon on the floor.
All in all, it was a very pleasant experience.