Milles, Knight of Anal Tyranny ~Impregnated by Lusty Tentacles at the Ends of Oblivion~

Waking up in the forest with no memories, the knight Milles finds her way to the land of Schnarb -- where peace is maintained by offering sacrifices to the local god Diva -- and meets the bounty hunter Cadia. The two hit it off, and Milles decides to make her living as a bounty hunter.

Meanwhile, the Queen of Schnarb, Regina, refuses to accept the sacrifice-hungry deity as a god and plans to arrange the escape of this year's sacrifice: the young girl Sadin. For Sadin to escape, she must first cross the forest where Diva sleeps...

Even as she feels the unconscious terror of Diva, her memories draw into the woods. At the end of oblivion, her memories will awaken... When Milles's raison d'etre is revealed, everything shall begin--

[From MangaGamer]