Atago Maru was a merchant ship built prior to World War II in Glasgow in 1924 by Lithgows & Sons for Nippon Yusen.

On 28 November 1944, the vessel was bombed by a United States Army Air Forces bomber while at anchor off Borneo.

[3] Atago Maru was built as a general cargo freighter for Nippon Yusen by Lithgows & Sons at Glasgow, Scotland with the yard number 762.

[3] The cargo ship operated between Kobe / Yokohama and the west coast of the United States and Canada, where Atago Maru found great success on the Seattle route.

On 3 August 1942, Atago Maru joined Convoy 425 sailing from Cap St Jacques, Vietnam bound for Mako, Pescadores.

On 28 December, Atago Maru began conversion to an emergency oil tanker at Sasebo Naval Arsenal, Japan.

Four days later the oil tanker joined Convoy MI-06 sailing for Moji, arriving on 17 July after stops at Manila and Takao.

[3] On 29 August, Atago Maru joined Convoy MI-14 departing Miri, making stops at Manila and Takao, and reaching Moji on 20 September.