I think the BIGGEST turn-off that everyone immediately has is the title. They probably could’ve worded it ANY better, but PLEASE trust me when I tell you how amazing it is. Obviously, the idea that you kiss your girlfriend’s sister is freaking weird, and I would get why that would be a big reason to not read the light novel/manga. But this isn’t a simple cheating light novel/manga, as it opened up so much perspectives (for me at least). I put mixed feelings because the plot can seem so unappealing, and I totally respect that. I do want to say, however, that this series just makesyou go “WTF” as you keep reading, whether that “WTF” goes from disgust, to surprise, to just that feeling of needing a break from what you just read (whether that is out of disgust or just how sad and just crazy it might be).
This is honestly amazing. For me personally, it just opened up so much perspectives like I had said before, and made me feel so many complex emotions all at once. I love this series so much just because of how different it was from a lot of other ones I read merely because of how complex it made me feel.
In conclusion, it can be a really unappealing series just because of how weird and degenerate the plot feels. But as you read (a lot into the series), you start having these contrasting emotions making you wonder how it will truly end? For me personally, it had opened up new perspectives for me and made me feel so many complex emotions.