The MV Kinai Maru was an 8360 gross ton freighter built by Mitsubishi Shipbuilding & Engineering Company Ltd, Nagasaki, Japan, in 1930 for Osaka Shosen Kaisha for the Yokohama-New York cargo run. Launched on 1 April 1930 and completed on 15 June, she was slated for an express service between Yokohama and New York. She broke the industry standard of 35 days by covering the route in 25 days. She plied this route until the outbreak of World War II and was requisitioned into Imperial Japanese Navy as a transport in late 1941. Employed in support of Japan's war effort she participated in landing troops at the battle of Milne Bay. On 10 May 1943, she was torpedoed by the submarine USS Plunger near Truk at 0400. Stopped in the water Tatsutake Maru comes alongside and starts transferring the 4,000 passengers and troops. At 0748 Plunger torpedoes Tatsutake Maru while she is still alongside Kinai Maru and Tatsutake Maru sinks by the stern at 14-29N, 149-23E. At 1253, Plunger finds Kinai Maru still afloat and torpedoes her again, without sinking her. The Japanese torpedo boat Hiyodori rescues the survivors of Tatsutake Maru and Kinai Maru and leaves the area. Still afloat on 11 May at 0600, Plunger surfaces and sinks her by gunfire at 14-33N, 149-23E.