These are all but useless in a sea battle outside littoral waters. Small missile boats like those are only useful in confined waters where they can hide in background clutter of land.
This is why ocean going navies rarely build this sort of ship. It's much like PT or MTB boats in WW2. They too are generally useless as combatants and pretty much confined to areas where you are dealing with coastal waters.
Nanuchka can do a little better with draught slightly more range , maybe like destroyer escorts of WW2
I doubt the soviet navy would challenge the japanese on the high seas esp not without extensive submarine or support from AVMF regiments
most likely battlefields for such a scenario would be
Japanese trying to blockade the soviet naval bases around vladivostock or around the Kuril islands and maybe infiltrate the sea of Okhost.