Practically all of the sea's islands are either in coastal waters or belong to the various islands making up the Kuril Islands chain which fall either under undisputed Japanese or Russian ownership or disputed ownership between Japan and Russia.
Practically all of the sea's islands are either in coastal waters. Practically all of the sea's islands belong to the various islands. These various islands are making up the Kuril Islands chain or disputed ownership between Japan and Russia. This Kuril Islands chain fall either under undisputed Japanese. This Kuril Islands chain fall either under Russian ownership.