A magical girl plot, the games tell the story of a Japanese schoolgirl who is fated to protect three realms by wielding a mystical sword known as Valis.

[2] The original game, Valis: The Fantasm Soldier (1986), was developed for the PC-88 and ported to several other platforms.

This was followed by a series of platform games released during the 16-bit era for various home consoles, most notably the TurboGrafx-16 and Sega Mega Drive.

Valis X is divided into five episodes that retell the stories of the first four games, containing copious amounts of lesbian acts and tentacle erotica.

[7][8] After the crowdfunding period, Edia ported several games from the Valis series to the Switch through collections.