According to Ministry of Health, a Japanese man from Fukuoka Prefecture complained of a high fever after returning from a trip to Guinea in Africa. He returned from Guinea on May 9th and reported his high fever in the night on 17th. He was taken to Fukuoka Higashi Medical Center, a medical institution for infectious diseases. He additionally complained of headaches and back pain. He said that he was not in contact with ebola patients in Guinea. Results of his test have been sent to the Infectious Disease Surveillance Center in Tokyo for further analysis.
Source: Yahoo News / May 18