Choko Maru was a Japanese cargo ship of 3,515 tons. The movement record at combinedfleet.com says Tama Zosensho laid her down on 6 February 1939 for Taiyo Kogyo of Kobe, launched her on 1 June 1939 and completed her on 30 November 1939. The Navy took her as an auxiliary transport in 1941. This is not the stores ship sunk west of Saipan by Tang, and not Choko Maru No. 2.
She left Truk on 23 November 1943 for Kwajalein in a convoy with an auxiliary water tanker and an auxiliary transport, escorted by a cable layer and a submarine chaser, and arrived on 1 December. On 5 December 1943 a Task Force 51 air strike of 27 dive bombers and torpedo bombers hit ships in the atoll while she was still unloading fuel drums and other cargo. Combinedfleet.com says two bombs struck her No. 4 hold and engine room and started fires, and that a bomb from a second strike set her No. 5 hold ablaze in a large explosion. Her crew fought the fires for the rest of the day. On 6 December the fires spread, her holds and engine room flooded, and she listed and was abandoned. She sank by the stern about 1.5 miles west-southwest of Little Bustard Island, and four crewmen were killed. Some dive accounts date the raid 4 December and call the wreck Barracuda Junction. No single aircraft is credited with the kill.
She was removed from the Navy List on 5 February 1944.