Goof: When Kotoro pins Kyo and company in place he says it is because his shuriken have pierced their shadows. However the shadows were not pierced with shuriken but with kunai.
The scroll painting you see briefly during the scene when the two ladies are talking privately in Ieyasu's castle is of a Baku, a mythical animal usually depicted as being either like a tapir (as in this case) or as an elephant headed lion-like beast. In Japanese Taoist mythology(also in China), Bakus are believed to have the power to consume bad dreams. Baku images are therefore often placed around a persons sleeping area (particularly a child's)this means that the conversation is probably taking place in one or the other of the ladies' private bedrooms.
Anachronism: When Yukimura captures Kyoshiro she says that the bill he skipped out on was for eighty-five sen. This is an anachronism as japan did not adopt the sen (note to those unfamiliar with Japanese currency 100 sen =1 yen) as part of its currency till 1871 over two hundred years later.