Shizen is one of the four main islands of Asuka, and the smallest island after Higa. It is south of Kita and east of Mori. Shizen’s ancient names include Meiyo no shima, “Island of honor”名誉の島, Kumo okoshi toki “the place at which clouds arise” 雲起時 (modern雲が発生する) and Owai- basho “the place of celebration” (お賀いの場所)。

There are seven provinces that make up the island: Obu, Izumo, Kata, Mikawa, Atsu-hime, Makata and Kabe.