Development of the PS-1 has its origins in flying boat research performed by the Shin Meiwa during the 1950s. The company, believing that their design was capable of regular use upon the open sea, petitioned the Japanese military to acquire the type as a maritime patrol aircraft (MPA). Following the demonstration of a converted Grumman HU-16 Albatross testbed aircraft, referred to as the UF-XS, the Japan Maritime Self-Defense Force (JMSDF) awarded Shin Meiwa a contract in 1966 to further develop its design via two further prototypes, which were designated PS-X. During 1969, the JMSDF placed the first order for an eventual fleet of 21 ASW aircraft, designated PS-1; orders for the SAR variant, designated US-1A, were also issued during the 1970s.