North Korea began the war armed with the Shpagin PPSh41 Burp Gun as the standard personal weapon for submachine gunners. The CCF also used it, but employed a bewildering array of other automatic weapons, as well, possibly including Japanese guns such as the Type 100 which had been used in Southern China in 1942 by Japanese Marines.

Type 100 (1944)

The Type 100 was designed for ease of production, like the Bergman MP18, but using the underpowered 8mm Nambu round and firing automatic-only from an open bolt with a side-mounted, 30-round detachable box magazine which gave poor weapon balance. It was unreliable in combat use, mainly because of an elaborate ammo feed which often resulted in stoppages.

The Type 100 may be fitted with a bipod, and comes in three basic models:
With fixed stock and bayonet lug bar, possibly also with a compensator.
With folding stock and bayonet lug bar.
c1944, with fixed stock, bayonet lug on barrel jacket, compensator, and fixed aperture-type rear sight.

Causes of the Korean Tragedy ... Failure of Leadership, Intelligence and Preparation

The Foundations of Freedom are the Courage of Ordinary People and Quality of our Arms