Yeah, seems to me it was a prototype from 1945. Likenesses appeared in either the Strikers 1945 videogame or perhaps Raiden Fighters... Popular enough, but the name eludes me too!
Actually, the J7W is likely to be the inspiration, but is tagged as "Sanka Mk. B" here.
"The aircraft in this film were designed to represent the ultimate in propeller aircraft development, so the strong resemblance of this fictional aircraft to the Kyushu J7W "Shinden" is probably anything but coincidental." http://www.hlj.com/product/ORG02141
