My paper looks at "signatures" in the form of "ciphers" (kao) and other personal marks made on population registers, town rules, and apostasy oaths in the early seventeenth century to provide some empirical evidence of very high literacy among village leaders. The essay also argues, using the same data, that literacy had already begun to spread to household heads, particularly those in cities as well as to farming communities that were engaged in commerce. Signatures on documents--never before used for literacy study in Japan as far as I know--also provide some hints of early literacy among women in commercial farming families. Wide differences in the spread of literacy in cities and in the rural areas of the country are also clearly evident in these documents through analysis of signatures and other personal marks made on oaths and petitions. (Contains 18 notes.)