I am a particular fan of their Type 89 50mm Grenade Projector ("Knee Mortar"): fired a 1 1/4 pound spin-stabilized round with almost a pound of TNT filler and excellent fragmentation out to 325 meters accurately. According to some sources, accounted for nearly 60% of our Pacific War casualties. Darn thing could also fire their standard hand grenade by adding a screw-on booster out to 150m. We need a new version of that thing right now.
What I remember about that was Allied soldiers took the “knee” part of it seriously and tried to fire captured examples with the thing braced against their leg. Tough way to get a broken femur.