New JAL lounges are supposed to open July 19th...until then, they are very underwhelming. We just flew ORD-NRT-PEK and PVG-NRT-LAX in business...the AA Admirals Club at Narita is much, much nicer than any JL lounge that we saw, but perhaps that will change with the new lounge. You should have access to the Admirals Club based on being in JL business.
Sakura lounge at ORD is very underwhelming. Small and dark - there is a selection of free self-service drinks and some snacks, but nothing to write home about. It is almost directly in front of the security checkpoint in the International Terminal at ORD.
I have a thread over in the AA forum comparing JL and AA transpacific business service. IMO, JL is much better...and JL has started to upgrade their meal service, starting w/ the ORD-NRT leg.