Noodles
Japanese noodles often substitute a rice-based meal. Soba (thin, grayish-brown noodles containing buckwheat flour) and udon (thick wheat noodles) are the main traditional noodles.
Japanese noodles, such as soba and udon, are eaten as a standalone, and usually not with a side dish, in terms of general custom. It may have toppings, but they are called gu (具?). But the fried battered shrimp tempura sitting in a bowl of tempura-soba would be referred to as "the shrimp" or "the tempura", and not so much be referred to as a topping (gu). The identical toppings, if served as a dish to be eaten with plain white rice could be called okazu, so these terms are context-sensitive.
Hot noodles are usually served in a bowl already steeped in their broth and are called kakesoba or kakeudon. Cold soba arrives unseasoned and heaped atop a zaru or seiro, and are picked up with a chopstick and dunk in its dip sauce. The broth is soy-dashi-mirin type of mix, the dip is similar but more concentrated (heavier on soy sauce).
In the simple form, yakumi (condiments and spices) such as shichimi, nori, finely chopped scallions, wasabi, etc. are added to the noodles, besides the broth/dip sauce.
Udon may also be eaten in kama-age style, piping hot straight out of the boiling pot, and eaten with plain soy sauce and sometimes with raw egg also.
Read more about this topic: Japanese Cuisine