The Sea of Japan is also connected to the Pacific Ocean through the Tsugaru Strait between Hokkaido and Honshu while it is connected to the East China Sea through the Eastern Channel of the Tsushima Strait between Kyushu and Tsushima Island as well as through the Korea Strait between Tsushima Island and South Korea.
また、北海道と本州の間の津軽海峡では太平洋と、九州と対馬島の間の対馬海峡東水道、対馬島と韓国の間の朝鮮海峡で東シナ海と繋がっている。