“That looks just like an ME262.”
It was based on a description of an Me-262 by the Japanese Military Attache from his witnessing a display of the aircraft in 1944. The engine was based on the BMW-003 turbojet, which the Japanese apparently had some information on. The Me-262 used the JUMO-004.
https://en.wikipedia.org/wiki/Nakajima_Kikka
The Japanese prototype didn’t have the swept wings of the Me-262, but was otherwise the same.
The Japanese also were testing an Me-163 clone.
Kinda surprised they didn’t test a Natter, though.