Hime Dorei: Mesu e to Ochiyuku Futago no Oujo  

姫奴隷～牝へと堕ちゆく双子の王女～

In the northern part of the continent lies the powerful Luvence Kingdom, which rules over its region with an iron fist. The king has two lovely sisters, Tita and Liese. Despite their close bond, when the king declares that Tita will be his successor to the throne, Liese is filled with rage and begins to despise her sister. One day, a magician named Waldo arrives in the kingdom. His homeland was destroyed by the Luvence army, and he seeks revenge against them. By chance, Waldo crosses paths with Liese. The plot for revenge against the kingdom and the girl who hates Tita begins to unfold.