Japan actually has a pretty huge navy though technically it's just a "self-defense force". And it's blue-water capable, something that even China's navy isn't. Hilariously enough, Japan also has a couple of helicopter carriers, but for some reason, classified them as destroyers!

So, pretty confident that Japan can wreck Russia's navy with their forces. Again, all Russia really has left are their nukes

Sounds to me like Putin forgot what happened in the Russo-Japanese War of 1904.