The east China sea is between China and japan that is point c.
East Coast of China: The East China Sea is located along the east coast of China, stretching from Shandong Province in the north to Fujian Province in the south.
Yellow Sea: You can find the Yellow Sea to the north of the East China Sea, separated by the Shandong Peninsula.
Taiwan: The island of Taiwan borders the East China Sea to the east.
Japan: The Ryukyu Islands of Japan form the eastern boundary of the East China Sea.