When you said you found the Tashiro mark on this, which I posted awhile ago, I forgot to reply that I'd found the company, Toshiro Shoten Ltd., in Yokohama, which until 1937 produced a line of eggshell porcelain, intricately hand-decorated, and, most interestingly, that used many Kutani-trained artists. Hence, the look of Kutani.
I put the update here for the benefit of anyone else who comes across the mark. KB