In 1944 mass production was preparing another model of the plane - Н8К2 M. 22 with a retractable top turret firing points, without blisters and with a retractable in-flight floats on the consoles of the wing. Two of the prototype during the tests, has set a new engines Mitsubishi МК4В Casey 25 takeoff power 1825 HP, after which the modification was designated Н8К4 M. 23. These machines had the highest for "Emily" speed of 472 km/h, but commercially they are not built as factories of the company "Kawanishi" urgently redeveloped on the issue of interceptors to protect the Islands of the metropolis.