There really is a difference when you see a character enjoying sex and not enjoying sex. In this situation, she was shown enjoying the gangbang and not really resenting it that I felt like it's alright.
Anyways, this story is like those horror stories wherein the main character is really desperate for something then suddenly a shop shows up having the very thing they desperately need. The main character then eats up what the shopkeeper says and in the end, the MC will get greedy and then at the end, they became one of the goods in the shop. That's the whole vibe I got from this, only, it has a virgin (victim) and a shop full of good looking people to fuck them up after (figuratively and literally).
Omochikaeri Ikemen Shop Ouchi de Juppori Tasting