The "Wa or 和" in Wagyu means Japanese and
"Gyu or 牛" means Cow.
Just as the name implies, Wagyu refers only to the specific strain bred in, and unique to Japan. Wagyu is the Queen of all breeds. Compared to other breeds, 100% genetically pure Wagyu has excellent marbling or intramuscular fat.
Japan is a country that started consuming steak 200 years ago, and it impresses us how quickly they were able to create the highest quality steak in the world. Not to mention that Japan is an island with a lot of natural disasters, and they were still capable of creating a beef industry that is known worldwide for its standardized and superior quality.