After Japan opened itself to the world over a hundred years ago japanese cooks began to adapt western dishes in their own style. For instance in the west people use ketchup as a condiment but the japanese use it as a base for tomato sauces in 'Naporitan' pasta. Spaghetti 'Naporitan' was created just after world war 2 after Shigetada (the head chef at the Hotel New Grand in Yokohama) saw occupying soldiers eating it. Nowadays you can find spaghetti seasoned with soy sauce and served with seaweed. I have always been a huge fan of japanese-style pasta and decided to make my own version!
Devine & I spent many evenings at Saizeriya a cheap japanese chain of family-style italian restaurants. I had my very first yoshoku-style (western style) pasta there. There are better yoshoku restaurants in Tokyo but they don't have cheap wine.
I of course preferred to make my own at home I think adding soy sauce to pasta is brilliant. Using buckwheat soba noodles is certainly not very western I think adding soy sauce to pasta is brilliant. Using buckwheat soba noodles is certainly not very western but it's what i felt like having at the time. This recipe could be made using regular pasta it would taste just as good.
There are a lot of warnings concerning hijiki but as is the case for most foods... moderation is key.