Mishima beef (見島牛 Mishima gyu) is a type of beef produced in Japan that is much rarer than Kobe beef. Natural monument. It is named after the tiny Mishima Island in the Sea of Japan 40 km northwest of Yamaguchi Prefecture. The progenitors of the Kobe and Mishima cattle were probably brought to Japan by ancestors of the modern Japanese people over 2,000 years ago. Whereas Kobe beef is the result of breeding these with European cattle, the Mishima have never been crossed with modern European breeds. This is possible because of the area's unique island geography.
Every restaurant worth their fancy salt has given wagyu beef a go in the last few years. It's so common (and bastardised) now that you even see it as wagyu burgers and pies. So what is the new step up from this, apart from having producer branded 100% wagyu cuts on your menu?
Mishima could be the answer. Mishima is the original Japanese cow, fortunately they lived isolated in the Sea of Japan on Mishima Island and were not cross breed with European cows in the late 1800's. The Japanese cross bred cows eventually became the Kobe (in Kobe -Japan) and wagyu (in Japan, Australia and the US) cows that we now are familiar with. The Mishima cows were able to stay pure bred and retain their unique marbling qualities when fed solely on grass.
These pure, native cows became so rare that sources suggest that there was less than 100 beasts left in the early 1980's. The meat is so prized and rare, because only 10-12 male cows can be sold in every year.