As noodle dishes, ramen is very popular in Japan- as I mentioned, TSUKEMEN is recently getting popular, too. More traditionally, UDON and SOBA are very popular in Japan.
UDON is made from wheat flour. It is usually thicker than ramen noodle.
SOBA is made from buckwheat flour. So the color is grayish. The thickness is similar to ramen noodle.
Both of them are eaten with Japanese traditional broth- Hot and cold dishes are available.
Generally speaking, UDON is more popular in KANSAI, on the other hand, SOBA is more popular in TOKYO area.
Cold UDON seasoned with grated DAIKON radish, spring onion, SUDACHI citrus and soy sauce.
The side dish is TENPURA of chopped vegetables and cutlet of a slice of ham.
Cold SOBA with soy sauce based broth with half a boiled egg and
The side dish is TENPURA of chopped vegetables, a conger and a MAITAKE mushroom.