If you didn't have an obsy, I would have said any of the new strainwave mounts. They are so light and portable and balancing is no longer needed.
but since you have an obsy, well, focus on obsy-class mounts! Any reason for the made-in-Japan request? Many mounts from around the world are exceptional these days.
What's your budget? If I had the chance, I'd look at a 10micron mount, maybe the 2000 because it leaves room for a scope upgrade.
https://www.testar.com.au/collection...0-hps-ii-combi
But it's not cheap. So maybe the 1000 instead (still not cheap, but observatory class mounts really aren't)
https://www.testar.com.au/collection...ron-gm1000-hps