Greeting:
Learn to bow, although Japanese may not care as much because they would expect us dumb foreigners to just shake hands. Bow lower than anyone superior to you. Don't be surprised of someone bows and shakes. If you know Japanese, there are certain phrases when meeting for the first time, too. Business cards have their own ceremony. Present yours with 2 hands, J side up (if you have both languages), and with the writing facing the other person so they can read it. Receive one with both hands, too, don't put it away and DON'T put it in your wallet! Look at it and see if you can pronounce the name slowly.
Greetings can also include what to day and do with a receptionist.
Dress code:
Always wear a suit or equivalent, and make it conservative.
Hierarchy:
You will know who is boss, usually the eldest. Behave as if he's God. He usually is in his section.
Direct eye contact:
Minimal.
Distance between people:
Have never measured.
Physical contact:
Handshaking ok, but expect limp shakes from most.
Slashing motion downward with the hand to open a space to walk in crowded quarters. Usually no contact with the other people, although some is accepted by us rude, dumb foreigners. LOTS of physical contact on crowded trains and subways, but people usually shoulder their way through instead of pushing. In business gatherings, no real contact is usually done anyway.
Showing emotions.
J show these only when very happy or extremely upset, and usually remain stoic or pensive. Foreigners should, too.
Expect and allow for longer silences, and not show emotions then.
Sexism.
Yes, it exists. Women are usually treated as inferiors to serve tea and carry things. Foreign women I've worked with are treated as bra fillers, so expect ogling at any time. Have never seen a female J superior, but they exist.