Based on the adult game by Erectlip.

Henrietta is a Royal Princess who is in charge of protecting the Prince aka (Also Known as) his own brother Emilio. One day suddenly the kingdom was attacked and everything was destroyed. However, there is a rescuer who came Helga but still they got captured by the Bandits. When imprisoned, their Bandits were asked to become prostitutes and to satisfy the bandits.

(Source: Nekopoi and Has Been Translated)