According to the Japanese, Ministry of Defence, Japan has launched the F-X program.
They describe the program as follows:
The Japan-led F-X development program to succeed the Japan Air Self-Defense Force (JASDF) F-2 fighter jet has started in Japan’s fiscal year 2020. “Air superiority” which is the basic premise for the JSDF operations, can be regarded as what is called “public goods”, essential for the defense of Japan.
In order to secure this “air superiority” into the future, it is vitally important to develop the next fighter jet with excellent performance, freedom of modification, future upgrade potential, and domestic defense infrastructure for maintenance and repairs, as the successor of the F-2, which is scheduled to start retiring around 2035.
Following the policy that MOD/SDF will “launch a Japan-led development project at an early timing with the possibility of international collaboration in sight” as set forth in the Medium Term Defense Program (FY 2019 – FY 2023), the MOD has made a contract with Mitsubishi Heavy Industries and embarked on the F-X development on October 30th, 2020.
In addition, in December 2020, the MOD has released the direction of international collaboration on the F-X development as follows.
In developing the F-X, the MOD has decided to advance this program with necessary support and cooperation from the U.S., such as selecting the U.S. company Lockheed Martin as the candidate for an integration support company, and starting a new project with the U.S. from next fiscal year to ensure interoperability between Japan and the U.S.
Also, the MOD will continue discussions with the U.S. and the UK to pursue possibility of collaboration on the F-X at system level such as engine and avionics in order to reduce development cost and technical risk.
The development of the F-X is an extraordinarily large program compared to the MOD’s previous aircraft development projects. In order to make this grand program a success, the MOD will develop the F-X by making maximum use of technological and human resources possessed by domestic companies and further strengthening collaboration between the government and companies, and between the companies, as well as considering the direction of international collaboration as mentioned above.
Also, see the following:
The featured graphic is the concept design of the F-X fighter as proposed by Mitsubishi.