We have multiple examples during the game that Hana is neither a prude nor has she many social hangups, but in the case of family, she is more traditionally inclined, mainly because of how she grew up. We can gleam from conversations with her that Hana´s childhood and adolescense had it´s share of serious problems, with later on August coming into the mix as well.
It is not surprising that Hana wants a boyfriend who takes the relationship seriously.
Hana isn't a prude, but I don't think she was ever a libertine either, even before she got dragged into August's orbit. She's fine with casual sex under the right circumstances - and the current circumstances with the MC and the Club qualify. But if she's going to commit to something more than then that she wants a genuine commitment in return. That's how I see it anyway.
I think it comes down to trust and I think that even from the moment you first meet Mina in the club with Killian the game makes it very clear that she already has had issues with him and doesn't trust him completely, despite her slightly naive attitude towards their relationship. She wants to explore these things but didn't trust Killian completely to do so, and let's face it, he makes it clear that he never really treated her particularly well from the start. I mean, he more or less outright admits that's how he has acted in all relationships.
So now Mina ends her relationship with him, finds some guy she thinks is actually trust-worthy and also is undergoing a bit of a moment of self-realisation. It's just all sort of adding up. If Killian had just earned her trust a bit more then possibly she might have asked him to help her explore (although you could also suggest that maybe she has some hang-ups over him being her first "boyfriend" and being too struck by the novelty of that all to make the move there)... Overall, I feel like the progress of her character makes good sense to me.
Plus, you have to account for porn game logic and the protagonist has a magic cock so...
Trust is at the heart of it, but there's more to it than just the MC being a designated protagonist. I think there's also a complete failure of communication between Mina and Killian.
If Ian was called out on his treatment of Mina back in the prologue his response was quite dismissive:
Beyond his less than lively respect for women, this is also demonstrates Ian's extremely poor read of Mina. Mina comports herself as a simple, innocent girl so he looks no further than that. It never occurs to him that beneath her shiny, pink exterior there's a bundle of sexually-repressed neuroses eager for a chance to cut loose. Ian sees only what he's conditioned to see from a 'good' girl. So rather than recognize an opportunity when when, say, Mina oh-so-subtly interrogates Hana about her lesbian experience, Ian crudely teases her about it then goes to get his jollies with some floozy instead of his girlfriend.
Now Mina was indeed raised to be the sort of girl Ian is expecting, and as a result she's intensely uncomfortable expressing her sexual urges. With Ian simultaneously dismissing her hints and implying she's no great shakes in bed, it's no wonder Mina was never comfortable letting the mask drop and sharing her dark fantasies with Ian. The MC was slightly different because Mina specifically wanted to cheat on Ian with him; she
needs to drop the mask at least a little to make that happen. Combine that with the MC's *vastly* superior emotional intelligence allowing him to recognize the implications of Mina's actions and BAM! he gets the fast lane to pervy town that Ian never knew existed.
On a totally different note, I'm playing through 4.2 now and it's finally fucking happened. The moment where you have to choose between some of the girls. I knew it was coming and have currently decided to go with the "lie your pants off and shag everyone" route, but godamn it made me feel like an absolute asshole for doing so.
As always, very few games absolutely nail the porn as well as Pale Carnations while simultaneously also making me so invested in the characters. I said almost exactly this at the last update, but HOW DARE YOU Mutt and Jeff make me feel so bad for just wanting the porn... When that choice inevitably comes back to bite me I'm gonna be bloody furious...
Hmph. Serves you right, you monster!!
