Hey cowbell.
I'd say your guitar is a loose interpretation of a Rickenbacker 325 which was made famous by John Lennon during the early Beatle years. It's difficult to say who made it without spending a bit of time in the VintAxe Catalog Library. Although most Japanese companies focused on Fender/Gibson copies, I think Greco and Burny made Rickenbacker copies in the Mid-Late 70's. Ibanez/Hoshino also marketed 4001 basses as I recall.
Since you bought the guitar in Japan it is also very possible it was made by one of the smaller domestic builders. It is my understanding that Rickenbacker lawyers vigorously pursued legal action against companies that copied their designs which is one of the reasons you don't see more Rickenbacker copy guitars in the US.
You clearly "smuggled" one in