Men or Menai means the rate of Koso (an annual tax) to the Kokudaka (the annual yield of a land) in the Edo period.
Men originally meant the rest of the Kokudaka after deduction of Koso which farmers were allowed to use without restraint. However, after early Edo period, it came to be used to indicate the rate of Koso.
It is generally referred to as Men-yottsu (forty percent for the government, sixty percent for citizens) or Men-itsutsu (fifty percent for the government, fifty percent for citizens). Although it actually varied depending on the financial condition of a feudal lord, the feudal estate or each land condition, and the rate was often defined in tenths, hundredths or thousandths, and in the Kyoto-Osaka area, Men was called 'Rin tori' (literally, collecting in units of Rin) because the rate was fixed to Rin. For example, if the rate is 'Men-yottsu(4) roku(6)-bu yon(4)-rin kyu(9)-mo', 46.49% of the kokudaka, which is 46-koku four-to and seven-sho, is supposed to be paid. At that time, Mura-uke Sei (tax system that placed responsibility for payment on villages) was employed, and there were two types of men: 'Komen' for the kokudaka of a Village and '毛付面' for the kokudaka of a village after deduction of non arable land and losses, and both of them were often written in the certificate by a feudal lord.
In the Edo period, there were two methods of taxation. The Kemi-ho Method which assessed Men based on the yield, employed in the early Edo period (Kemi-ho is also divided into Sebiki Kemi, which was commonly employed in the early Edo period, and Arige Kemi which appeared later, and Sebiki Kemi is further divided into Dandori Sebiki, which was mainly employed in Kanto region, and Rindori Sebiki, which was common in Kyoto-Osaka area), and the Jomen-ho Method which assesses Men based on the average yield during a certain period, which was adopted by the Edo Shogunate and became wide spread after the Kyoho era.