[4] While she was making 13 to 14 knots (24 to 26 km/h; 15 to 16 mph) on the surface northwest of Marcus Island on 12 August 1943, the submerged United States Navy submarine USS Tarpon (SS-175) sighted her at 17:27 Kilo Time.

[4] Observing Ro-105 through Tarpon′s periscope, Tarpon′s commanding officer described her as an "I-153-class submarine" with the Japanese "merchant ship flag" and "D-105" painted on her conning tower.

On 25 September 1943, she joined the submarine Ro-109 and eleven destroyers in covering the evacuation of Japanese forces from Kolombangara in the central Solomons.

[4] She reached Sarmi on 9 October 1943, unloaded her cargo, and got back underway the same night for the return voyage.

[4] Ro-105′s lookouts observed star shells and gun flashes from the battle in the distance early in the morning of 2 November.

[4] The Japanese light cruiser Sendai and destroyer Hatsukaze were sunk during the battle, and later on 2 November 1943 Ro-105 received orders to search for their survivors.

[4] She arrived there on 18 November 1943, unloaded her cargo, and then put back to sea to patrol off New Britain in the Arawe-Cape Merkus area.

[4] She got underway for Sarmi again on 6 December 1943, carrying a cargo of 7 metric tons of ammunition, provisions, stores, and medicine for the Imperial Japanese Army forces on New Guinea, and 4 metric tons of cargo in rubber bags on deck for Navy forces on the island.

[4] When she arrived at Sarmi on 8 December 1943, she could not unload due a breakdown in communications with Japanese forces ashore and withdrew.

[4] Leaving Sarmi the same day, she again patrolled in the Arawe-Cape Merkus area before returning to Rabaul on 20 December 1943.

[4] While at sea on 1 January 1944, she received orders to intercept U.S. Navy Task Force 74, which a Japanese patrol plane reported north of Choiseul.

[4] The picket line was tasked with providing warning of any move toward the Palau Islands by Allied invasion forces.

[4] On 18 May 1944, U.S. Navy signals intelligence personnel intercepted and decrypted Japanese signals indicating the formation of Scouting Line NA between Truk and the Admiralties, and a hunter-killer group composed of the destroyer escorts USS England (DE-635), USS George (DE-697), and USS Raby (DE-698) departed Purvis Bay in the Solomon Islands to intercept the submarine I-16, then attack the submarines assigned to Scouting Line NA.

[4][7] By 27 May 1944, when the three destroyer escorts put in to Seeadler Harbor on Manus Island in the Admiralties to replenish their ammunition,[4] England had sunk I-16,[7] Ro-106,[8] Ro-104,[9] Ro-116,[10] and Ro-108.

[4] Ro-105 was on the surface north of the Admiralty Islands on 30 May 1944 when Hazelwood established radar contact on her at a range of 6,000 yards (5,500 m) at 01:44.

[4] Ro-105 submerged and disappeared from Hazelwood′s radar at 01:53, but Hazelwood quickly gained sonar contact on her and mounted a depth-charge attack.

[4] Oil began to reach the surface two hours later within 500 yards (460 m) of the sinking, and the American ships recovered debris from the water.

[12][11] On 25 June 1944, the Imperial Japanese Navy declared Ro-105 to be presumed lost north of the Admiralty Islands with all 55 men on board.