With the inevitable invasion of the Japanese home islands coming the Japanese Army, on January 20, 1945, ordered Nakajima to build a suicide attack aircraft. It had to be easy to manufacture, maintain, and fly.
Engineer Aori Kunihiro, Mitaka Kenkyujo (Mitaka Research Institute), and Ota Seisakusho K.K. (Ota Manufacturing Co. Ltd) designed the Nakajima Ki-115a Suicide Attacker Tsurugi (saber).
The wings were all metal and the fuselage had a steel structure. The tail had a wood frame.
The undercarriage was made to be jettisoned after take off.