Japan Current or Kuroshio (kŏŏrōshē´ō)[Jap.,=black stream], warm ocean current of the Pacific Ocean, off E Asia. A northward flowing branch of the North Equatorial Current, it runs E of Taiwan and Japan; the Tsushima Current separates from the main current and flows into the Sea of Japan. At about lat. 35°N it divides to form an eastern branch flowing nearly to the Hawaiian Islands and a northern branch that skirts the coast of Asia and merges with the waters of the cold Oyashio Current to form the North Pacific Current. Dense fogs develop along the boundary between the Japan and Oyashio currents. Air moving over the warm Japan Current becomes more temperate and acts to moderate the climate of Taiwan and Japan.