The bodies of water that touch or are near Japan are the Philippine Sea, Sea of Japan, Korean Straight, and the Pacific Ocean. The South China Sea does not touch Japan.
It is the Korea Strait that separates Korea and Japan.
Sea of Japan, Korea Bay, and maybe the Yellow Sea
Battle of Korea Strait happened on 1950-06-25.
the countries of Korea and Japan
A sea passage between Korea and Japan
The Korea Strait.
japan and south Korea
Japan and South Korea
The Yellow Sea
Either the Korea Strait or the Sea of Japan.
If the three main southern islands you are referring to are the Ryukyu Islands, including Okinawa, and the rest of Japan referring to the 4 main islands of Japan, then the answer is the East China Sea. If the three main southern islands you are referring to are Kyushu, Shikoku and Honshu, and the rest of Japan referring to Hokkaido, then the answer is the Tsugaru Strait.
The Korean Strait