Commissioned in 1938, I-8 was a Japanese Junsen III type cruiser submarine. Equipped with a hangar and catapult, she could carry a floatplane for reconnaissance, and had a range of 14,000 nautical miles. I-8 supported the attack on Pearl Harbor, in December, 1941, and conducted War Patrols until June, 1943, when she was sent to Europe. I-8's mission was to conduct a technology exchange with the Germans, and she traveled through the Indian and Atlantic Oceans to reach Breast, France, on 31 August, 1943. She was the only Axis submarine to successfully complete the round trip from Europe to Japan during the War. After her crew were given parties and state visits to Paris and Berlin, they once again set sail, returning to Japan in December. Unfortunately, I-8s achievement would be tarnished by her next crew, which brutally murdered the crews of at least two merchant ships they sank in the Indian Ocean, with probably several other incidents not known. At the end of 1944, I-8 was converted to carry Kaiten suicide torpedoes, and was sunk by US destroyers off Okinawa 31 March, 1945.