Travis Bruno of Capsule Computers writes:
" Many anime fans have likely heard of the Tenchi Muyo! anime franchise. In fact, for a number of fans, Tenchi Muyo! may have been one of the first anime series they watched. The franchise saw multiple anime series, a number of movies, and even a Magical Girl type spin-off. Of these series, the creator Masaki Kajishima has mentioned that amongst the various series, only one should be taken as canon, the Tenchi Muyo! Ryo-Ohki series which was followed up with Tenchi Muyo! GXP."