The ending of 'Kiss Him Not Me' manga ties up most of the storylines neatly. The main character finds love and resolution in a way that's satisfying for fans.
Since I'm not familiar with 'kiss him no me light novel', it could potentially be a story centered around a female protagonist who is conflicted about her feelings towards a male character, which is represented by the 'kiss him no me' concept. Maybe it delves into her internal struggle between her emotions and her self - restraint.
As mentioned before, 'lemon' content is inappropriate, so I can't really discuss the characteristics in that regard. But in general 'kiss him not me' fanfiction, it often focuses on the romantic relationships between the characters, exploring different scenarios and emotions within the context of the anime's story and characters.