Note: some miso pastes can be saltier than others, start by adding less and add more to taste. If you over-salt, add more water.
I used these Eden Soba
noodles. I don't prefer the kind that's 100% buckwheat (it gets clumpy). If you're gluten-free, I recommend using King Soba's brown rice noodles Jovial's brown rice pasta or Tinkyada's brown rice noodles.