Isekai NTR Inn: My Lover and Little Sister Are Taken from Me Before I Know It / 『異世界NTR旅館 ～恋人と妹が知らない間に奪われていく～ 【イセヤド】』 v.1.17

In an unfamiliar, otherworldly realm, their peaceful everyday life gradually begins to unravel under the influence of the local men...
The protagonist, Hiroto, his beloved Miyuki, and his younger sister Akari find themselves transported to another world, enveloped in a mysterious light.
The first place they end up is a small “hotel in another world.” While trying to find a way back home, the trio helps out with work at the hotel and gathers information. However, one day, after venturing into the forest with Clark, a mercenary and one of the hotel’s guests, they are attacked by monsters.
This incident becomes the starting point for cracks to gradually begin appearing in the relationships between the three protagonists...
On top of that, a new man named Dejar arrives at the hotel. Two sinister forces begin to reach out toward the people dear to Hiroto: Miyuki and Akari...
This game is an NTR simulator with real-time event progression, where the heroines live their own lives and act independently of the player while he makes his decisions.