In the first chapter there are already choices that will fundamentally affect the further passage (say, the hero can determine for himself the desire to meet with his ‘neighbour’ or not). But that doesn't take the story of the ‘neighbour’ character out of the game. We will not have sex with her in the future unless we want to change our minds, but the full story of the neighbour and her participation in the life of the hero will not go anywhere.
And with the trans, fuck, well there's going to be a really cute hamster in there, I can't afford to make it opizonal, sorry.
With her there will be a soft variant, for those to whom it is well past (kisses, cuddles, nice conversations) and a little less soft variant (torment, wanking, sex, etc.).