Shanghai. Laid down at Kiangnan (Jiangnan Arsenal) Dock & Engineering Works (operated by Mitsubishi as Konan Yard) as a 2, 700-ton cargo ship for Nippon Yusen Kaisha (NYK Line) K.K., Tokyo.
17 October 1943: Launched and named SHIROHAMA MARU. 
26 December 1943: Completed.
17 February 1944: Requisitioned by the Imperial Japanese Army (IJA). Alloted IJA No. 1185.
26 February 1944:
SHIROHAMA MARU departs Moji escorting convoy MOTA-06 also consisting of with fleet storeship MUROTOSAN and DAISEI, GOZAN, ISHIKARI, LONDON, NICHIAN, NICHIYO, SAN PEDRO and TOYOKUNI MARUs escorted by kaibokan AWAJI.
29 February 1944:
Anchors at Ssu Chiao Shan.
1 March 1944:
At 0900 departs Ssu Chiao Shan.
4 March 1944:
At 1000 arrives at Takao.
7 March 1944:
SHIROHAMA MARU departs Takao for Palau in convoy Nishi-Matsu No. 1-TAPA-04 also consisting of ATSUTA, GOZAN, TAISEI, TAKEGAWA and TETSUYO MARUs and four unidentified merchants escorted by destroyers ASAGAO and HAMANAMI and torpedo boat SAGI.
12 March 1944:
ASAGAO detaches from the convoy to undertake an anti-submarine sweep.
14 March 1944:
Arrives at Palau.
5 April 1944:
At 0240, SHIROHAMA MARU departs Imari Wan (Bay) in convoy MOTA-16 also consisting of HIROTA, MITSU, NITTETSU, SHONAN. TACHIBANA, TENSHIN, TOSHO and YAMASACHI MARUs escorted by minesweeper W-18 and patrol boat PB-38. At 1845, anchors off Raro Retto, Chosen (South Korea).
6 April 1944:
At 0530, departs Raro Retto.
8 April 1944:
At 0637, arrives at Ssu Chiao Shan (now Sijao Island). At 1054, departs there with auxiliary gunboat CHOHAKUSAN MARU as an additional escort.
10 April 1944: At 0700, CHOHAKUSAN MARU is detached.
11 April 1944:
At 1027, arrives at Takao.
15 April 1944:
At 1244, SHIROHAMA MARU departs Takao in convoy TAMA-16 also consisting of cargo ships BIZEN, OMINE, , SORACHI, SHONAN and TOSHO MARUs and YOSHIDA MARU No. 3, fleet tanker ASHIZURI and tankers HAKUBASAN, MATSUMOTO, NITTETSU, TACHIBANA, TAKETSU (BUTSU), YAMAKO (SANKO) MARUs, OGURA MARU No. 1 and YAMAMIZU MARU No. 2 and two unidentified merchants escorted by light cruiser KISO, destroyer HASU, torpedo boats HAYABUSA and SAGI, patrol boat PB-38 and auxiliary subchasers CHa-9 and TAKUNAN MARU No. 3.
17 April 1944:
At 0725, torpedo boat HAYABUSA joins as an additional escort. At 1550, auxiliary gunboat KISO MARU and auxiliary subchaser CHa-39 also join as additional escorts.
18 April 1944:
Detached escorts HASU and TAKUNAN MARU No. 3 arrive back at Takao.
19 April 1944:
At 1312, arrives at Manila.
15 May 1944:
SHIROHAMA MARU departs Manila for Halmahera Island in convoy H-26 also consisting of AKAGISAN, DAIJUN, ETAJIMA, KENWA, TAIYU, TEMPEI and TOUN MARUs and SHINSEI MARU No. 1 escorted by minelayer YAEYAMA, minesweeper W-48 and subchasers CH-45 and CH-47. The convoy carries the 110th, 117th, 119th, 120th and 122nd Airfield Battalions, 123rd and 124th Field Airfield Construction Units. The two Field Airfield Construction Units were semi-mechanized units (equipment one prime mover and 13 trucks each) of about 149-179 soldiers and civilians each. Each field airfield construction unit supervised 1,000-2,000 local employees.
21 May 1944:
At 0410, USN codebreakers intercept and decrypt a message from YAEYAMA that reads: “Torpedo attack on convoy [H-26] in position 06-15W, 127-15N.”
22 May 1944:
Off Davao, Philippines. At about 0100, LtCdr (later Rear Admiral-Ret) Brooks J. Harral's (USNA ’32) USS RAY (SS-271) makes a radar-assisted night attack on the surface on the convoy. In a series of attacks, Harral torpedoes TEMPEI MARU carrying a cargo of gasoline and rice. The gasoline erupts in flames. She sinks at 05-16S, 127-42E. 11 passengers, five gunners and 19 crewmen are KIA.
23 May 1944:
At about 0500, USS RAY makes a surface radar-assisted attack and torpedoes DAIJUN MARU carrying 16 passengers, 4,022 cubic meters of war supplies and two Daihatsu barges. She sinks at 02-42N, 128-08E. Two gunners and three crewmen are KIA. Late that day, the remainder of H-26 arrives at Kau Bay, Halmahera.
1 June 1944:
Arrives at Onagawa.
15 July 1944:
At 0500, SHIROHAMA MARU departs Kau, Halmahera Island in convoy M-27 also consisting of HAVRE and RYOCHI MARUs escorted by patrol boat PB-104 and subchasers CH-41 and CH-46.
16 July 1944:
At 0100, arrives at Bitung.
21 July 1944:
Departs Bitung for Manila.
5 August 1944:
N coast of Celebes. Beaton Bay. SHIROHAMA MARU, while berthing, is bombed and destroyed by USAAF 5th Air Force North American B-25 "Mitchell" medium bombers at 5.00N, 123.00 E. 
7 August 1944:
 Also known as SHIRAHAMA MARU.
 Another source says SHIROHAMA MARU sank off Boetoeng, Api Island, southern Celebes, 04-40'S, 122-47'E.
Thanks go to Erich Muehlthaler of Germany.