Until mid 19th century, almost all Japanese did not eat beef at all. Cows and bulls existed in Japan but they were used as a labor force, working on rice fields.
After Japan abolished its isolation policy, Europeans and Americans moved in to Japan and made changes to Japanese lifestyles including foods. Then, big consumption of beef came and Japan tried to make a suitable beef for their cuisines. Which means more tender as possible. Therefore history of Wagyu beef is less than 200 years!
American BBQ is done outside at the garden but Japanese style is mostly done inside the building, using a portable cooking stove. The stove can be heated by gas or charcoal and iron nest or plate are put on the stove.
Teppanyaki in US or Europe are cooked by the chefs at the restaurant but Japanese BBQ is cooked by the customers by themselves. Usually you choose the meat(beef, pork or chicken), seafood and vegetables. Meats are sliced in thin pieces and vegetables are cut into small pieces too.
Then you grill the meat, seafood and vegetables and when it is eatable, you will dip into the sauce.
Many Japanese BBQ restaurants offer ALL YOU CAN EAT too. Then, most of the restaurants offering ALL YOU CAN EAT offer ALL YOU CAN DRINK too. However, there will be a fine if you have a leftovers of foods. Then, you cannot order multiple drinks at once but you will get the next drink when you exchange your empty glass.