Central Pacific

On 6 December 1941, Ro-66 and Ro-67 got underway from Kwajalein to conduct a reconnaissance of Wake Island,^[4] which the Japanese planned to invade on 8 December 1941, the first day of the war on Wake Island′s side of the International Date Line, while Ro-65 reconnoitered Roi in the Marshall Islands before joining Ro-66 and Ro-67 off Wake in time for the invasion.^[5] The Battle of Wake Island began on 8 December 1941, with Ro-65, Ro-66, and Ro-67 patrolling in the area supporting Japanese forces attempting to seize the atoll.^[4] United States Marine Corps forces defending Wake drove back the initial Japanese assault that day.^[4] Ro-67 conducted her first war patrol, operating off Wake until 13 December 1941.^[3] She then returned to Kwajalein, which she reached in company with Ro-65 on 17 December 1941.^[3] Ultimately, the Battle of Wake Island concluded on 23 December 1941 with the Japanese conquest of the atoll.^[3]

Ro-67 departed Kwajalein on 24 December 1941 to begin her second war patrol.^[3] Engine trouble forced her to turn back, however, and she returned to Kwajalein on 25 December 1941.^[3]

On 16 January 1942, Ro-67 got underway in company with Ro-65 to support the Japanese invasion of Rabaul on New Britain in the Admiralty Islands, ordered to patrol south of Cape St. George on New Ireland.^[3] On 21 January 1942, the two submarines received orders to join the submarines of Submarine Division 33 — Ro-63, Ro-64, and Ro-68 — in patrolling in St. George's Channel while Japanese forces landed at Rabaul, but they found no targets.^[3][5] Ro-65 and Ro-67 arrived at Truk on 29 January 1942.^[3][5]

On 10 February 1942, Submarine Division 27 was disbanded and Ro-65 and Ro-67 were reassigned to Submarine Division 26.^[2][5] The two submarines departed Truk on 18 February 1942 with orders to reconnoiter the Butaritari area in the Gilbert Islands, proceeding to Butaritari after calling at Ponape in the Caroline Islands from 28 February to 3 March 1942.^[3][5] After completing the reconnaissance, the two submarines headed for Japan, calling at Jaluit Atoll in the Marshall Islands from 17 to 18 March 1942 and at Saipan in the Marshall Islands from 24 to 27 March before proceeding to Sasebo, which they reached on 2 April 1942.^[3][5]

Aleutian Islands campaign

On 14 July 1942, Submarine Division 26 was reassigned to the 5th Fleet^[3] for service in the Aleutian Islands, where the Aleutian Islands campaign had begun in June 1942 with the Japanese occupation of Attu and Kiska. On 10 September 1942, Ro-65 and Ro-67 departed Sasebo, then called at Ōminato, Japan, from 13 to 15 September and at Paramushiro in the northern Kurile Islands from 19 to 21 September before proceeding to their new operating base at Kiska, which they reached on 26 September 1942.^[3] Almost as soon as they arrived, American aircraft attacked the harbor.^[3] The planes strafed Ro-67 repeatedly and scored near-misses with several bombs, knocking out both of her periscopes and both of her electric motors.^[3] The damage forced her to head back to Ōminato for repairs.^[5] She arrived at Ōminato on 4 October 1942.^[3]

Training duties

Ro-67 departed Ōminato on 9 October 1942^[3] and arrived at Yokosuka, Japan, on 12 October 1942.^[3] On 15 November 1942, Submarine Division 26 was reassigned to the Kure Submarine Squadron, and thereafter Ro-67 served as a training submarine.^[3] She was reassigned to Submarine Division 33 in the Kure Submarine Squadron on 1 December 1943.^[2]

Ro-67 was in drydock for repairs at the Kure Naval Arsenal at Kure, Japan, on 19 March 1945 when the United States Navy′s Task Force 58 launched the first Allied air strike against the naval arsenal.^[3] More than 240 aircraft from the aircraft carriers USS Essex (CV-9), USS Intrepid (CV-11), USS Hornet (CV-12), USS Wasp (CV-18), USS Hancock (CV-19), USS Bennington (CV-20), and USS Belleau Wood (CVL-24) attacked Japanese ships in the harbor at Kure, and American aircraft repeatedly strafed Ro-67, killing 13 members of her crew.^[3]