It doesn't end up as NTR but I don't think they end up together either. I don't understand japanese, but as I saw in the raws, I think the author leaves their relationship open without any conclusion.
Am I the only One Who thinks this actually makes sense with what the series said they were going to do? They literally wanted to 'restart' the relationship like a game, so they just confessed once again, like restarting a Game. Not saying its realistic, cuz ofc its not, but since both of them...