The Ki-116 was essentially the last variant of the Nakajima Ki-84 Hayate to enter flight trials. It was originally the fourth Mansyu-built Ki-84-I, and adapted to take a 1,500 hp Mitsubishi Ha-112-II (aka Kinsei 62) engine, the same engine as used in the Kawasaki Ki-100, driving a three-blade popeller borrowed from a Mitsubishi Ki-46-III Dinah. This conversion proved to be very successful, and a reduction of 1,000 lb in empty weight being registered. The aircraft was still undergoing tests at the time of Japan's final defeat. The plane seemed to have been somewhat longer and had an increased tail surface area as compared to the original Ki-84.
This plane was created as a fighter-interceptor. There is no indication this aircraft was intended for the Special Attack suicide role (shimbu-tai).
One aircraft built at Manshūkoku Hikōki Seizo KK at their plant in Harbin in 1945.