Could Russia have invaded a Japan defended only by coastal ships?

If Japan had possessed only coastal-defence ships before the Russo-Japanese War, could Russia have invaded?

Probably not; Japan would still have had numerous local defenders, and Russian naval weaknesses were the larger problem.

The counterfactual removes Japan's ocean-going battle fleet and substitutes coastal-defence ships. A Russian invasion still seems unlikely. Japan would have possessed more local defenders and probably would have handled them better than the Russian Navy handled its own force. The answer shifts attention from platform labels to command, readiness, and operational competence.