The KI44 and J2M get an undeserved reputation as non-turning bricks that climb and go fast for one reason.
Most of the reports on these two plane's maneuvering were first impression reports by pilots who had just transitioned to them from the KI43 and the Zero.
Reports from pilots who had more experience in the types were very different.
They turn very well with the maneuvering flaps and match up favorably against most allied planes.