Takasago Maru was a passenger-cargo liner of OSK Line which later transferred to the Imperial Japanese Navy as a hospital ship.

[2] On 12 November 1941, she was acquired by the Imperial Japanese Navy and converted to a hospital ship by Kure Naval Arsenal on 1 December.

USS Pilotfish encountered Takasago Maru on 5 February 1945 and was let go as she was clearly marked as a hospital ship.

USS Murray conducted an onboard search for violations and contrabands but found her to be clear and let her continue to Wake Island on 2 July.

While she was in Maizuru on 25 July, planes from the aircraft carrier USS Yorktown attacked the harbor but with no hits on Takasago Maru.