The result was the Mikasa (ミカサ) class, which was a smaller, lighter version of the Mikai-class 2-8-2s already in service,[1] and 43 were built in Japan for Mantetsu in 1934 by Kawasaki, Kisha Seizō, Hitachi, and Nippon Sharyō.

Numbered 1400 through 1442, the last 22 - 1421 through 1442 - were built with a sloped tender designed to allow greater rearwards visibility during shunting operations.

Like the Sorisa-class, they were fitted with a regauging device to allow operation on Russian 1,524 mm (5 ft 0 in) gauge lines, in anticipation of a possible Japanese invasion of the Soviet Far East.

[1] A number of Mikaro-class locomotives were loaned to the West Chosen Central Railway in 1944–45 to alleviate power shortages on that line.

At the request of the Kwantung Army, the Dalian Machine Works (other sources say Mitsubishi's Kobe Shipyards[3]) built a single experimental condenser version of the Mikaro class in 1941.

In tests, Mikaku 501 recorded 1,600 km (990 mi) without taking on more water, but the design was never put into production.

[4] It is probable that the last 120 locos were never built as the highest number reported, JF6 3475, is one of the final batch and carries Shenyang 1959 plates.

In 1947, the US military ordered five Mikaro-class locomotives for the Korean National Railroad of South Korea from Kisha Seizō;[1][10] These, together with the former Sentetsu Mika1 and Mika2 class locomotives that the KNR had converted to run on lignite in the early 1950s, were designated Mika6 (미카6) class by the KNR.