TonenGeneral imported Japan's first cargo of Kurdish crude from northern Iraq in January, a source with direct knowledge of the matter said on Tuesday.
Iraq's semi-autonomous Kurdistan region began selling oil directly to world markets in 2015 to get money for its survival and to fight Islamic State. Typically, Kurdish oil, exported via Turkey's Mediterranean port of Ceyhan, has gone to Europe.
TonenGeneral imported about 1 million barrels of Kurdish oil last month, classified as "export blend of Iraqi origin" in data from the Ministry of Economy, Trade and Industry's (METI).
The cargo was delivered to TonenGeneral's refineries in Kawasaki and Chiba, both of them near Tokyo, according to the source and Ministry of Finance data.
TonenGeneral declined to comment on the deal.
Security threats have for now halted the Kurdish crude exports after a pipeline to Ceyhan was unexpectedly shut in February.
(Reporting by Florence Tan and Osamu Tsukimori; Editing by Tom Hogue)