At the dinner table:
-Never leave chopsticks sticking in your food. This is considered very rude. Instead, leave them laying flat together along the side of your plate.
-It IS appropriate to make noise when sipping noodles in soup. The air sucked in with hot noodles helps cool the noodles to avoid burns.
Japanese are very careful about showing their mouth.
-You must cover your mouth when giggling, sneezing, or yawning. Women must cover their mouths with an open hand, and men can make a fist.
-Japanese do not ever spit in public (don't even think about shooting "snot rockets.";)
Sitting without a chair:
-Only men should sit "Indian style" with legs crossed, as it is considered the masculine casual way.
-Women must sit with their knees together, underneath or bent to one side.
In respect to pedestrians and traffic:
- Cars are much more respectful of pedestrians waiting to cross a street, and cars who don't stop for pedestrians on base will be ticketed.
- If cars are not stopping at a cross-walk, Japanese raise their arm to alert cars (like asking permission to ask a question in class)
Japanese are always very appreciative of others efforts and gifts.
-It is customary to bring a small gift when invited to a Japanese home, and often for apologies.
-Never give money to apologize for a vehicle crash. These must be reported, and if money is exchanged, it would just be gone.
Garbage and recyclables:
-Japanese are VERY strict about sorting plastics, metals, glass, and "combustables." These are things like paper waste, disposable diapers, food and lawn waste.
-Do not ever throw a can or bottle into a "combustable" container. Always look for the appropriate container. This is great for the environment.
This definitely doesn't cover everything, but hopefully these "rules" help you avoid an awkward situation in Japan.