Completed and commissioned in October 1943, she served in World War II, operating off the Admiralty Islands, in the Indian Ocean — where she sank the last Allied ship torpedoed by a Japanese submarine during World War II — and off the Philippine Islands.

[1] For surface running, the boats were powered by two 500-brake-horsepower (373 kW) diesel engines, each driving one propeller shaft.

[4] While conducting a simulated torpedo attack in the Seto Inland Sea on 9 November 1943, she collided with the battleship Yamashiro in the Iyo Nada, suffering minor damage and no casualties.

[4] She departed Kure, Japan, on 23 February 1944 for her first combat operation, an antisubmarine patrol in the Ryukyu Islands under the direction of the Grand Escort Command.

[4] On 6 November 1944 she torpedoed and sank the British 3,827-gross register ton merchant ship Marion Moller — the last Allied ship torpedoed by a Japanese submarine in the Indian Ocean[4] — in the Bay of Bengal at 10°40′N 081°10′E / 10.667°N 81.167°E / 10.667; 81.167 (Marion Moller).

[4] Ro-113 began her third war patrol on 28 November 1944, again tasked with attacking Allied shipping in the Bay of Bengal.

[4] A Royal Air Force Liberator bomber attacked her in the Bay of Bengal off Madras, India, on 3 December 1944, but she survived undamaged.

[4] On 4 February 1945, the 6th Fleet ordered Ro-113 and the submarines Ro-46, Ro-112, and Ro-115 to proceed to Takao, Formosa, unload their reserve torpedoes and deck gun ammunition there, and then head for Batulinao on the northern coast of Luzon to rescue Imperial Japanese Navy Air Service pilots stranded in Luzon's Aparri area and transport them to Takao.

[4] Ro-113 was on the surface in the Luzon Strait in the vicinity of Babuyan Island north of Luzon in the predawn darkness of 13 February 1945 when the U.S. Navy submarine USS Batfish (SS-310) detected her on radar at 02:15 bearing 220 degrees from Batfish at a range of 10,700 yards (9,780 m).

[4] On 20 February 1945, the Imperial Japanese Navy declared Ro-113 to be presumed lost in the Luzon Strait with all 59 men on board.