FAMOUS AIRCRAFT OF THE WORLD No124 said that N1K5-J had a MK9A engine. Basically MK9A was a turbocharged high altitude engine.
But seeing this drawing I feel this engine was a MK9B which Kawanishi J3K had.
MK9B engine(Ha-43-21 series) : Vulcan coupling drive first stage and mechanical drive (two speed?) second stage supercharger. If N1K5-J had a MK9B, this drawing was consistent.
If N1K5-J had a turbocharged MK9A engine, intercooler air intake and ram air intake for turbocharger are needed.
Engine nacelle bottom air intake of this drawing is small, so it was only for oil cooler.
I can see only engine nacelle side air intakes.
If it were intercooler air intakes, I can't find ram air intake in this drawing.
If it were ram air intakes for turbocharger, I can't find intercooler air intake.
Also I can't find turbocharger in this drawing.