天地無用!魎皇鬼
The long-running OVA series, and the inaugural entry of the [[Tenchi Muyou!]] franchise.

Five series have been produced to the present date. The first series was released from September 25, 1992 to September 25, 1993, the second from September 25, 1994 to September 25, 1994, the third from September 18, 2003 to September 9, 2005, and the fourth from November 30, 2016 to September 13, 2017. Releases of the fifth ran from February 28, 2020 through May 28, 2021.

The series [[Tenchi Muyou! GXP]] and [[Isekai no Seikishi Monogatari]] ("Tenchi Muyo! War on Geminar") both take place within the continuity of [i]Ryou-ouki[/i].
tenchi muyou! ryou-ouki