The ship left the yard in early February 1945, conducted sea trials, and arrived at the Mare Island Navy Yard, Vallejo, California on 18 February to take on an amphibious craft. She then visited Seattle, Washington for additional repair work. On 10 March, the vessel got underway for Hawaii and reached Pearl Harbor on the 23rd.
LST-31 left Hawaii on April 4 for Okinawa. She embarked passengers and loaded supplies at Eniwetok and Guam before proceeding on to the Rykys and anchoring in waters off southwestern Okinawa on May 3. She remained in the area for approximately three weeks providing logistic support to troops fighting on Okinawa. The ship arrived at Ulithi on 28 May; took on cargo; and in June, set a course for the island of Leyte in the Philippines. During the months of June, July, and August, LST-31 operated between the Philippines and Okinawa, transporting supplies and troops between the two points to build up Okinawa as a base for the conquest of the Japanese home islands. However, this invasion was obviated when Japan capitulated on Aug. 15. The ship then began moving occupation troops and equipment to Japan from various points in the Philippines. She first arrived in Japanese waters on Sept. 15, when she dropped anchor in Tokyo Bay.
On Nov. 30, LST-31 was assigned to duty in Japan with the 5th Fleet, Amphibious Group 11, LST Flotilla 35. However, these orders were superseded late in December; and the ship was slated for decommissioning. She was scheduled to be turned over to the Japanese merchant marine to be manned by a Japanese crew under American control for use in repatriating Japanese citizens and shuttling supplies between Japanese ports.
After the ship was stripped of all armament and other wartime equipment, LST-31 was decommissioned on 8 January 1946 and transferred to the Japanese. The vessel operated under Japanese control into May 1948, when she was returned to U.S. Naval custody. She left Yokohama on the 3rd of that month and shaped a course for the west coast of the United States. The tank landing ship was later berthed in the Seattle area. Her name was struck from the Naval Vessel Register in August 1955 and she was subsequently sunk as a target.