1. East China Sea, South Korea--Japan Ōse-zaki to Cheju-do Yale Public content 1994. 2011-12-16T16:42:24Z. 2015-10-21T15:07:56Z. United States. Defense Mapping Agency. The Agency. English. Public. East China Sea, Cheju Strait (Korea), Korea Strait, Japan, Goto Islands, Korea, and Cheju-do.