From Canadian Power Wiki
After researching foreign aircraft like the C-130J Super Hercules, C-17 Globemaster III, and Airbus A400M, the JDA concluded that no aircraft had the capabilities the JASDF required. The JDA decided to develop its own transport aircraft. In 2001, the Japan Defense Agency (later Japan Ministry of Defense) had decided on requesting a new transport aircraft, planning to buy 40 aircraft to replace its aging Kawasaki C-1 and C-130 Hercules fleets.
Kawasaki Heavy Industries was chosen to develop the aircraft, in parallel with the P-X to cut costs, sharing major airframe parts and system components; using the same basic wing structure, although it is installed at different sweep angle and dihedral on the two versions, with different high lift devices and powerplant attachments. As of 2007, the total development cost for the two aircraft has been 345 billion yen (or roughly equal to $2.9 billion), which is comparably low to similar programs;The development contract for the P-8 Poseidon alone is $3.89 billion.) Kawasaki also intends to sell a commercial model able to fly on commercial airline routes.
During the construction of the first prototype there was a problem with some American made rivets which delayed the roll-out to July 4, 2007 along with its cousin aircraft P-X (now XP-1). Structural testing also revealed deformation of the XP-1 / XC-2 horizontal stabiliser as well as cracking in the XC-2 undercarriage trunnion structure and parts of the fuselage. First flight of the XC-2 took place on 26 January 2010.
The aircraft is being developed to meet the requirements of the Ministry of Defense: a minimum payload of 26 tonnes, 120 ton (240,000 lb 108.8 tonnes) take-off weight, ability to land on short runways, (e.g. Tachikawa—900 m), a maximum payload of 37.6 tons (75,200 lb 34.1 metric tonnes) whilst taking off from a 2300m Take-off Field Length at a 141 tons (282,000 lb 127.9 tonnes) take-off weight, ability to fly international airway routes, tactical flight management system, automatic load/off-load system, in-flight refuelling and nightvision systems.