Air Self-Defense Force's next fighter - Coordinating with the United Kingdom for common aircraft development

Recently CNN.co.jp reported the following:

航空自衛隊の次期戦闘機 イギリスと共通の機体開発で調整

2022年9月4日 4時58分

航空自衛隊の次期戦闘機をめぐり、防衛省は開発費の抑制などのため、エンジンの共同研究を行っているイギリスと共通の機体を開発する方向で調整を進めています。

航空自衛隊のF2戦闘機の後継となる次期戦闘機をめぐっては、ことし1月から日本とイギリスの大手企業がエンジンの共同研究を始めていて、5月の日英首脳会談では開発に関する両国間の協力の全体像をことしの年末までに合意することで一致しました。

これを受けて防衛省は、次期戦闘機に求める性能がイギリスとほぼ同じで、開発費も抑制できるとして、共通の機体を開発する方向で調整を進めています。

また、共同開発には、戦闘機の開発でイギリスと協力関係にあるイタリアの参加も検討されています。

防衛省は来年度予算案の概算要求に次期戦闘機の開発費などとして1432億円を盛り込んでいて、F2戦闘機の退役が始まる2035年ごろまでに次期戦闘機の配備を始めたいとしています。

Translation

Regarding the Air Self-Defense Force's next-generation fighter, the Ministry of Defense which was already conducting joint research on engines, in order to control development costs was making adjustments to develop a common airframe with the United Kingdom.

Regarding the next-generation fighter that would succeed the Air Self-Defense Force's F2 fighter, major Japanese and British companies had started joint research on the engine since January this year, and at the Japan-UK summit meeting in May they shared the view that they could agree on an overall picture of cooperation by the end of this year.

In response to this, the Ministry of Defense was proceeding with coordination in the direction of developing a common aircraft as its performance requirement for the next fighter was almost the same as that of the UK, and the development costs could be suppressed.

In addition, the joint development was also considering the participation of Italy which had a cooperative relationship with the United Kingdom in the development of fighter aircraft.

The Ministry of Defense had included 143.2 billion yen in the budget request for the next fiscal year's budget proposal for development costs for the next-generation fighter, and wanted to start deploying the next-generation fighter by around 2035, when the F2 fighters would retire.

So, Japan’s Air Self-Defense Force will develop a common airframe with the United Kingdom for it's next-generation F2 fighter in order to control development costs. My understanding it that currently Japan is also using F-35 fighter jet bought from the US.