This is one of the most important seasonings for Japanese cooking.
For making Japanese dishes, I strongly recommend soy sauce which is made only by soy, salt, wheat (and water).
In Australia, You can find many kinds of soy sauce and many of them often contains sugar, MSG or some more.
But authentic Japanese soy sauce is made by soy, salt and wheat… that’s all. And almost all of Japanese recipes ( include mine) may be written on the assumption that you are using such JAPANESE soy sauce.
So if you want to enjoy Japanese cooking, please be careful about ingredients of soy sauce.
Soy sauce is used for lots of Japanese dishes and I think that’s not too much to say that the taste of soy sauce decides the taste of the dish totally.
To use good-quality soy sauce will assures you that your Japanese cooking goes very well (even though there are limited products you can get in Western Australia).
In this website, I write recipes as using kikkoman soy-sauce(made in Singapore) for soy sauce. Maybe you can easily get it at common supermarkets.
You may want to use “Salt Reduced” or “Gulten Free” version, but I’m afraid I’m not sure whether it’s OK or not for my recipes because I have not used them.