Ōmi Code
The Ōmi Code are a collection of governing rules compiled in 668AD, hence being the first collection of Ritsuryō laws in classical Japan. These laws were compiled by Fujiwara no Kamatari under the order of Emperor Tenji. This collection of laws is now lost and its disputed existence is supported only by short references in later documents.
It is furthermore missing from the Nihon Shoki.
The Ōmi-ryō, consisting of 22 volumes, was promulgated in the last year of Tenji's reign. This legal codification is no longer extant, but it is said to have been refined in what is known as the Asuka Kiyomihara ritsu-ryō of 689; and these are understood to have been a forerunner of the Taihō ritsu-ryō of 701.