Gotcha.
What I meant is that in the intro and beggining, there's a LOT (and I mean, a LOT) of NTS teasing (things that happen in MC mind, as "delusions") but after ALL character are introduced and the initial quests completed, you have the option to engage OR not engage in netorase, or swinging, or X W Z play.
There's no "vanilla" route in a very clear defined sense, because you sharing the heroine will be an option depending on NTS rating stat, how much she is into that play, etc. I might need to rephrase or clarify that part of the overview, because that line really needs to be updated, now that you mention it.