I went to ARAKAWA river in Niigata prefecture, Japan.
ARAKAWA is most clear river in Japan. It is famous salmon river in Japan. Someone said that ARAKAWA is similar to ARASKA salmon river. River run fast. The amount of water is huge in ARAKAWA. Day after rainy day is good condition for salmon fishing in ARAKAWA. If the amount of water increase, many salmon run up the river.
The good fly is 10cm of red zonker. Best way is to retrieve fly in bottom.
My fishing result is 3 hooking off and 1 salmon, 1 small fishing.