Flogging (jozai or jokei) was one of the five sentences of the Ritsuryo law. It is a lightest punishment except whipping. It's a punishment to hit the back or the buttocks with a wooden cane. In the Taiyo Ritsuryo Code and the Yoro Ritsuryo Code it was merely recorded as "cane".
The size of the cane was specified to be about 12mm thick at the handle, about 9mm at the tip and a length of about 1,05m, and in order not to break the skin of the punished person, knags of the cane were sahved off. This cane was called jokojo. Similar canes were used for torture, but then they were called jinjo.
Convicts who were to be flogged were imprisoned without apparatuses. If the executor used a cane that is not compliant with the specified jokojo, or if the convict was severely or fatally injured, he could be subject to punishment. The number of strokes ranged from 60 strokes to 100 strokes in 5 steps, depending on the seriousness of the crime. A district manager had the authority to impose the punishment of whipping, but only the provincial governor had the right to decide flogging, in some cases, at his own discretion. If a crime was detected among the officials staying in Kyoto, the appropriate official had an exclusive right to decide a punishment lower than flogging. When a lower rank officer (chonai, shijin) acted against his master's orders, the master (honshu) himself was permitted to execute a punishment lower than flogging on his own.
It was also possible to avoid punishment by paying copper coins weighing the equivalent to the number of strokes of the cane (shokudo, or atonement by copper).
The beginning of flogging can at least be traced back to the sixth century, because there is a record in China's official history book Suisho (The Book of the Sui Dynasty) which says "in this world (…) otherwise depending on the severity (…) they get flogged", which shows that this kind of punishment existed in Yamato (Japan) at the beginning of the seventh century.