I do forget from time to time that Mystia is specifically a sparrow... 🤨 I mean, I guess I would assume a sparrow yōkai to be, well, fairy-sized. But Mystia more often than not is depicted with a bigger build than that.
Huh, yosuzume myth is... pretty localized. If we home in, then Mystia is probably from Kōchi/Tosa herself – the south side of Shikoku (starting region of Chosokabe, for Shogun 2 players). Shit, now I'm associating Mystia with bows now.
Out of topic at this point, but I think the reason why the Chosokabe gets extra farming income might be a reference to their Ichiryō Gusoku (though extra income is probably a bad reflection). The gist of the system is that the Chosokabe really embraced the boundary between farmers and warriors. Every peasant had one set of equipment (as opposed to samurai having multiple), and so they were very quick to muster (save for farming season), already fit and disciplined.