If it MUST be Japanese, your best bet is probably to find one that is reversably modified with features most mustang people don't want (ie. EMG pickups, or has some really oddball wiring), and then fix it up, that's what I usually do when it comes to Japanese Fenders, some people do some odd mods to those guitars, my Jaguar and Jag-Stang were both procured that way.
Another option is the Squier VM, which has a basswood body like a Japanese mustang, roughly the only difference is a flatter fretboard radius (9.5 vs. 7.16"), it has individually adjustable bridge saddles, and the logo on the headstock - and that it's most likely made by Cort (Cor-Tek) in Indoneisa.
