In Japan, beef is a luxury and therefore is used sparingly and for special occasions. In fact the famed Kobe Beef, from cattle breed and raised in Kobe, Japan can cost as much as $300 a pound. Because of the high cost of beef in Japan the usual tricks are used to make the most of it.
A typical steak that might be served individually in the United States is seasoned to perfection, carefully cooked, sliced thinly and served with rice, vegetables and/or tofu to spread it out. One point to make is that American Waygu beef is not really equivalent to true Japanese Kobi Beef.
The most recognized way of preparing steaks in Japan is teriyaki style. Teriyaki is all in the marinade. This mixture usually containing soy sauce, ginger, sugar and Sake or Mirin. This marinade/sauce can be used on most any meat, but for me the mixture of flavors, grilled over live coals goes best with a good steak.
To get the most from the marinade take the steak you are going to grill and make 1/4 inch slices into the surface of the meat at a 45-degree angle on both sides. This allows the flavor to get deep into the meat and cuts down on the time you need to marinate. Make the cuts across the grain and you will also increase the tenderness of the meat.
Next place the steak in the marinade and refrigerate for a couple of hours. The longer you let it sit the stronger the flavor will be. Once you are ready to cook just drop it on a hot grill. I usually reserve some marinade for serving, but make sure that if you use the marinade that the steak has been sitting in that you boil it for 5 minutes first.
When grilled to desired doneness simply slice into thin strips, across the grain and serve. It goes great with everything from rice to a vegetable stir fry.