The Mogami together with three cruisers of the same type- the Mikuma, the Suzuya and the Kumano- was designed and completed in 1935 as a large-scale light cruiser of an 8500-class. Protecting the Mogami was thickened, highly shell-proof armor effective in warding off extremely large falling-angle shells of U.S. heavy cruisers. But most impressive was the Mogami½s 152,000hp engine, the same employed on the battleship ½Yamato,½ the biggest battleship ever produced in the world. With the termination of the London Naval Reduction Treaty in 1937 the Mogami had its guns upgraded from 15.5cm triple to 20cm double guns. On March 30, 1942, the Mogami in cooperation the Mikuma and a squadr