MarkMan
loves Arcade Sticks
AFAIK the Retron 5 only works with legitimate retail games. The R5 supports ips patching for fan translations though, so you can import the legit JP version and play it in English that way.
https://www.youtube.com/watch?v=eh3N2Msdmgc
Thanks. I'm going to pick it up when I go to Japan next, then!