While Ganjin (Jianzhen), the founder of the Ritsu sect in Japan, obeyed the Shibun-ritsu (Four-Part Vinayapitaka, which explains about regulations and prohibited matters of the priests), Eison obeyed the Juju-ritsu (Ten-Reciting Vinayapitaka) that Kukai, the founder of the Shingon sect, valued.
日本律宗の祖である鑑真が「四分律」を奉じたのに対して、叡尊は真言宗を開いた空海が重んじた「十誦律」を奉じている。