Cute Knight Girl

As Tsukasa Kadoya's younger sister, Sayo Kadoya unexpectedly gets a System that lets her travel to worlds of Rider Girls and other worlds.

And so Sayo meets all kinds of Rider Girls and lovely young women from other worlds...

One day...

Daiki Kaito takes out a card and inserts it into his azure-blue gun.

"Garo, Shinga!"

A white-haired man who looks exactly like Tsukasa Kadoya is summoned.

Kaito points one hand at the sky and says slowly, "Sayo once said that only a demon can defeat a demon!"