No seriously, the plot so far sounds more like we're going to play some kind of fantastical Japanese Schutzstaffel. Apparently this was met with so little resistance that said secret police was able to set up an entire castle from which to plan the systematic subjugation of multiple species, and collude with various race traitors who sold out their own kind. Additionally, this secret police executes anyone who doesn't wear the magical star of david, which no doubt must have numbered in the thousands.
And yet, your game isn't about Japan erupting into a magical civil war over this specific thing.

If you'd like, I could probably very easily churn out a few ideas for the main plot that don't involve us being magical nazis but do leave room for honor, and loyalty, and other traditionally Japanese things. I can even arrange them by time period, if you'd like. And most if not all can easily incorporate magical stuff.

Also, you mentioned griffins, orcs, and elves. Those are all [i]extremely[/i] western fantasy races; orcs were codified in Lord of the Rings, and griffins originated in Greece and the surrounding areas. If your goal is to have a Japanese setting, you should exclude traditionally western races.