This is wonderful! Before your trip, you really need to prepare well enough! Let's check BSA's suggestions:
Prior to the trip -
1) Learn more Japanese
2) Learn more about the culture/customs/history
3) Bring more gifts for home stay family
4) Bring more money
5) Practice with chopsticks
6) Bring more trading items (patches, neckerchiefs, belts, Scout shirts, etc.)
7) Have business cards made with a picture (this is a great idea)
8) Bring candy for home stay family
9) Bring more film (or a bigger memory chip for digital camera)
10) Bring pictures of your American family, house, school, pets, etc.
11) Bring more hometown trinkets
12) Bring translator book or digital assistant
13) Bring Scout advancement badges to trade
14) Get a good passport carrier
Food Suggestions -
1) Try everything
2) Don't ask what it is until after you try it
3) Try items, then decide if you want more
4) Eat everything on your plate (see item #3)
5) Visit a Japanese restaurant at home before going to Japan
6) Don't judge food by looks
7) Normally there are not napkins (or condiments like salt/pepper) at tables
8) Bring your own sweets
9) The shrimp is great
10) Look at food on the Internet before the trip
11) Don't use too much Japanese mustard – it's HOT
For the rest, please click on the link.
