I think Rota went to the Hayashi Racing wheel shop and came back with a few wheels to reverse engineer; one being the Hayashi Racing Street to make the Rota BM8.
Here is the Rota BM8:
With an almost spokeless design they are popular on AE86 and other old school jap cars or people looking for a retro feel.
The small Japanese manufacturer Hayashi Racing manufacture a very similar looking wheel. Will Rota ever come up with their own designs?Google+