Earlier quoted context omitted.
No? They've expressed zero interest in resolving the disagreement via force, and parts of Ukraine are currently held by Russia in a similar fashion.
Then what was the point of your example? What does Japan gain from the idea that one country cannot take another country's territory by force, if it is in fact Russia that is in control of these islands? If anything, Japan would like them back eventually. All attempts at diplomacy have failed, so force would be the only other option.
That Japan most certainly doesn't want territorial disputes to be resolved by might and current possession status.
> If anything, Japan would like them back eventually.
Yes, and they'd prefer "Russia currently holds them, so they get to keep them" not to be precedent. Russia is attempting to set that precedent in eastern Ukraine, Georgia, and Moldova currently.