99 out of 100 games tease in first update, handjob in the 2nd, blowjob in the 3rd etc etc - very predictable and boring. None of that in this game, but it's not rushed in any way. The flow of the story is good and it's interesting and entertaining.
The key difference is the storytelling method. In most games, the world/story revolves around the MC, so any progress in them is basically shown by the progress of what the MC experienced (usually peeking first, then having a boner second, then handjob as first sexual act, and so on). It's like anything else doesn't exist if MC is not involved.
The good thing about this game is that the world/story doesn't necessarily revolve around the MC. The club already existed, it's the MC that entered the club. Regardless of what MC did/not, the club existed in the story with the other characters already having their own personalities and roles that are not determined by their relationships with the MC. So the storytelling is much tighter here because the world is alive.
As for romance, each character (this includes Hana and Mina) has their own "outside-the-club" difficulties that brought them to this point in the story and the player, if you're interested, can have a positive influence in helping them get over their personal hurdles.
Two questions on relationships if you don't mind:
1. Is it possible to have relationship with multiple girls at once? If yes, would they be treated separately or would there be group content?
2. How do you plan to allow/block relationships? You mentioned you plan to have 5 chapters, would there be a point where you're simply locked out of a relationship by the earlier chapters? Or in other words, do we have to always have the maximum points for each girl by 100% always choosing the right choices, or is there a leeway on making the wrong decisions? My plan is to play and make decisions how I feel, but even in Chapter 1 alone, I already saw that I wasn't close enough with Ian to share Felicia. All of that happened without me feeling like I was being a jerk to Ian throughout the game.
I guess what I'm trying to say is that I'm worried that the game would be one of those "must look at walkthrough to make the perfect choices" which ruins the immersion. If possible and not too late, I definitely think it's much better if the choices are more about "key choices" where it's obvious that they are important rather than where every choice is +1 or -1.