Susie, like you, I have a "fancy mouth" wrt Japanese food. As such, I'd like to opine that you're unlikely to find anything up to your standards in Nanjing. I suggest you reserve your Japanese food cravings for Beijing or Shanghai. You should be prepared to part with a fair amount of money (though not always; lots of nice 居酒屋 places in Shanghai), but will be able to avail of delicacies that are not on offer in Kansas City as long as you select the right restaurants.

Some second tier cities (e.g. Dalian, Shenyang, Qingdao) are on par with BJ and SH in terms of high end Japanese cuisine, but Nanjing is not among these ranks (check out your history book if you want to understand the "back story").