寝取られプリンセス～姫も女王も女騎士も、気付いた時には寝取られ済み～（Netorare Princess ~Hime mo Joou mo Onna Kishi mo, Kizuita Toki ni wa Netorare Zumi~）

Elencia, a princess and lovely flower of the kingdom, with whom the protagonist met by a finger of fate, traveled with, and swore to protect for the rest of his life.
Iris, Commander of the Imperial Guard, with whom the protagonist traveled and risked their lives to protect the princess.
Nadia, mother of Elencia and a beautiful empress, who saved the protagonist's life.

In his adventurous days after saving the princess, the protagonist of the story guards the kingdom in order to keep the heroines safe. The one he truly desired and loved was the princess—and yet, the fact that he managed to get her was nothing more than a dream.

He received a position and an honor, but he was still just one person. He lost his precious woman. Nefarious hands are drawing closer to the one he deeply loved, got out with, and became a lover with. Women get exposed before the eyes of men with different capacities and fetishes and fall into depravity.

The protagonist can only watch the heroines as they are defiled by lust. Are there zero happy endings?! This is the beginning of a full netorare adventure game!

[Translated from official site]