South Sea (Korea)

The Namhae (Hangul: 남해; Hanja: 南海; lit. South Sea), or Choson Namhae (Chosŏn'gŭl: 조선남해; Hancha: 朝鮮南海; lit. South Sea of Korea) in North Korea, is the region of ocean near Korea that is bounded by the southwestern part of the East Sea (Sea of Japan) and by the southeastern part of the West Sea (Yellow Sea). The name is not known and used outside Korea.

...
Wikipedia