Work began in 1956 on development of a fully tracked armored personnel carrier (APC) to equip the Japan Ground Self-Defense Force, with two prototypes being completed by Komatsu (the SU-I) and by Mitsubishi (the SU-II) in 1957.
Initial production orders were placed in 1959, and the type was standardised in 1960 as the Type 60 Armored Personnel Carrier [REF].