Ships
- IJN Mogami Captain from 10 April 1944
Ryo Toma became captain of the heavy cruiser Mogami on 10 April 1944. He was an officer of the Imperial Japanese Navy, and this was the command in which he was killed six months later. By the spring of 1944 Mogami had already been rebuilt after heavy damage at Midway in June 1942. She carried a reduced battery of heavy guns and a flight deck over the stern for floatplanes, so the ship Toma boarded was both a cruiser and a small aircraft platform. He relieved Ichiro Aitoku, who had been captain since April 1943. Seigo Sasaki had commanded the same ship from November 1942 until Aitoku took her.
In June 1944 the Combined Fleet put to sea to defend the Mariana Islands. Mogami joined Rear Admiral Takatsugu Jojima's carrier group, sailing with Junyo, Hiyo, Ryuho, and the battleship Nagato, in the body of the fleet behind Vice Admiral Takeo Kurita's vanguard. On 19 and 20 June the Battle of the Philippine Sea was fought in the air. Toma's cruiser stayed with the carriers while Japanese naval aircraft took losses the fleet could not make good. Mogami came out of the battle with the retiring force.
The next sortie followed the American landing on Leyte in October. In the plan to break into Leyte Gulf, Mogami was assigned to Vice Admiral Shoji Nishimura's southern force, with the battleships Fuso and Yamashiro and four destroyers. Their course ran from Brunei toward the southern entrance of Surigao Strait, timed so they would reach the gulf as a larger force came in from the north. The ships left Brunei on 22 October.
On the morning of 24 October Nishimura had Mogami send a floatplane over Leyte Gulf. The pilot reported battleships and cruisers, a large number of transports off the beaches, and destroyers and torpedo boats near the strait. An Allied force was already waiting across the northern end of the channel. Nishimura held on and entered the strait after dark.
In the first hours of 25 October the column moved up Surigao Strait. Patrol torpedo boats attacked early and were driven off. American destroyers then launched torpedoes in the dark, and Fuso dropped out of the line after being hit. Ahead of them, Rear Admiral Jesse B. Oldendorf's battleships and cruisers lay across the strait and opened fire. Smoke and burning ships made the view from Mogami's bridge difficult to read. Toma showed recognition lights toward vessels whose identity he could not make out, and shellfire came back. At about 4:02 a.m. hits on the compass bridge and the air-defense station killed Toma, his executive officer, and most of the officers posted there. The gunnery officer was left in command.
Mogami was on fire and losing way. She turned back down the strait and met the second Japanese group, under Vice Admiral Kiyohide Shima, still coming north. In the dark Shima's flagship, the heavy cruiser Nachi, collided with the burning Mogami, and both ships took further damage. Mogami continued south at low speed. After daylight, carrier aircraft found her and added bomb hits. Late in the morning the crew abandoned ship. The destroyer Akebono scuttled the cruiser with a torpedo, and Mogami sank by the bow at 1:07 p.m. on 25 October 1944 in Surigao Strait. Akebono took off about 700 survivors, 125 of them wounded. One hundred ninety-one members of the crew and one civilian worker were dead. Toma had already been killed on his own bridge, still captain of Mogami.