Japan ? Home of classic early 70's proto-metal ? Hellyeah ! There is Fromage, Foodbrain, Chronicle, Flower Travellin Band and the best named group in the universe, Flied Egg
Flied Egg were a trio of Shigeru Narumo (guitar, keyboards), Hiro Tsunoda (drums, vocals) and Masayoshi Takanaka (bass). They played a hogwash of progressive hard rock with pop-like flourishes all featuring English vocals.
They had 2 albums, Dr Diegels Fried Egg Shooting Machine ('72) and Good Bye (1973)
The second one is the highlight, clearly a precursor of stoner rock if ever i have heard one
Here's a great Youtube video to prove there were heaps of great early 70's proto-sludge bands