I believe smoke had it right with the Tojo.
The last aircraft destroyed before the Japanese surrender was downed by a P-61B-2 named "Lady in the Dark" of the 548th Night Fighter Squadron. The aircraft piloted by Lt. Robert W. Clyde and R/O Lt. Bruce K. LeFord on 14 August/15 August 1945 claimed a Nakajima Ki-44 "Tojo." It should be noted, though, that the destruction of the "Tojo" came without a shot being fired. After the pilot of the "Tojo" sighted the attacking P-61, he descended to wave-top level and began a series of evasive maneuvers which ended with his aircraft striking the water and exploding. Lts. Clyde and LeFord were never officially credited with this possible final kill of the war.