My niece married into a family of cattle farmers near Sapporo. They raise Wagyu but I was told they mostly raise the cross between Wagyu and black Angus. I learned from my niece and her husband that the wagyu is rather delicate and has to be housed in a barn during the cold snowy season but the cross breed with black Angus is much more robust and can stay outside in the snow and survive (and thrive).
This was certainly a great steak. (Of course, it was perfectly cooked, if I do say so myself). The wasabi flavor did not come through as much as I expected. Is it better than U.S. prime stake? I am not so sure. The oven fried potatos were excellent. They had a crunchy crust and creamy soft inside (my wife's contribution). We were still enjoying the wonderful 2007 Caymus Cabernet Sauvignon with this steak.