Shiden Kai 4
|Coastal Defense Ship||Destroyer|
|Light Cruiser||Torpedo Cruiser|
|Heavy Cruiser||Training Cruiser|
|Aviation Cruiser||Fast Battleship|
|Light Carrier||Standard Aircraft Carrier|
|Armored Carrier||Seaplane Tender|
|Submarine||Aircraft Carrying Submarine|
|Submarine Tender||Fleet Oiler|
This is an improved model of the carrier-based version of the interceptor aircraft "Shiden Kai", our trump card when it comes to our country's air defense. It is an upgraded version that improved upon the Shiden Kai's engine, featured excellent dogfighting capabilities due to high-horsepower engines, the use of flaps and was developed to fill in the spot that was reserved for its successor, the main fighter aircraft "Reppuu", as its deployment got delayed.
The Kawanishi N1K4-A Shisei Shiden Kai 4 (試製紫電改四 "Prototype Violet Lightning Modified 4") was a proposed carrier-based variant developed from the land-based interceptor fighter Shiden Model 32 Shiden Kai 3. It was equipped with a Homare Model 23 (N9KH-S) engine, armed with two Type 3 nose-mounted 13.2 mm machine guns and four Type 99 wing-mounted 20 mm machine guns; arresting gear was also installed. In the end, the development program for this aircraft was terminated due to the fact that the Imperial Japanese Navy did not possess any aircraft carriers to station the fighters by the time of its development. One prototype was built at Kawanishi's Naruo plant.
- The Homare Model 23 used a carburetor as its fuel combustion instead of the Model 21's direct fuel injection.
- The tail code written on the aircraft is ク-521, the kana symbol identifies the plane as part of the Kure Naval Air Group; meanwhile the digits represent the serial number of the aircraft.
- The Kure Naval Air Group mainly operated seaplanes aboard Japanese warships and Zero fighter detachments of the Iwakuni Naval Air Group, meaning that the Kawanishi fighter does not bear any connection to the Kure Naval Air Group.
- While it is unknown if the serial number is precise, it is known that the Shiden Model 32 Shiden Kai 3 prototypes spanned the serial numbers from 517 to 520.