@Redice I see, but I think Wagyu is born for export and tourist purpose, because for what I see in Ms. Bird manga, on that time for normal citizen, its not considered normal to eat cattle (because of their smell & they have high value for farming & transportation, they are treated like horse). Thats why in Japanese traditional dish, outside seafood there are many vegetable dish. Plus Japan base religion is Buddha, which eat vegetables as their main diet. In short its not required for them to eat meat.
So, why wagyu meat born? I think its because of Japanese emperor modernization program (which era is it? I forgot sorry), they want to appeal to the rest of the world, especially Europe. I dont think (on that time) European think vegetables is a luxurious dish, yes? Raw fish? Eeww.. So the only choice is cow meat.