So sexual encounters are an extremely important part of porn life sim games, so not sure why you used it as some kind of counter example.
That leaves story. Which is definitely not the majority the current gameplay at all. You have the intro, and Haven I guess? But Haven is mostly doing life sim stuff while waiting to investigate. And then you have the soccer team, which is just socializing and drinking (life sim), the dance club (which is an actual plot so far), and the photo club, which isnt much of anything aside some lewd images at this point. And a bit of the junkyard siblings. And while this is all great so far, the main gameplay loop is wake up, get ready, go to school or your job, maintain your stats, find opportunities to get fucked, experience some bits of story, get clean, go to sleep, then start all over. The majority of your time (after the intro) is not reading story beats. And I would like to point out that character stories you experience a bit at a time like the dance club and the junkyard siblings are a staple of the life sim genre anyway.
Also, read basically any of the changelogs and compare how much story has been added vs how many mechanics dealing with day to day living in this world have been added/tweaked. Maybe there's a reason it seems to be skewed completely towards one of those directions almost every update.
TL;DR: Story is not at all the main focus of this game, either development wise so far or in the current core gameplay loop. If it was, this would be a visual novel, which it isn't.