That's one of the reasons why I love Katie most of all.
In the beginning, the MC and her are pretty much not really friendly, and she sees him as "just another ghost." That relationship changes a very small bit once they head towards Mil-town, and it changes a bit more at and after the party, as well as the next meeting in her office.
Then, the relationship grows deeper when he spends the night in the chair, teases her, and they finally kiss and spend the night together. I mean yeah, it's pretty quick, but as you said, it's a porn game, but still, you build this relationship with her seemingly from the ground up, whereas Ellen & Chandy are really just booty calls.
You see a true, romantic, loving connection build between the MC and Katie. I know Ellen, if you go her route, everything changes that night when the MC kisses her, then she softens up a bit. She's still fiery, but you see her also allowing herself to soften.
Katie's scenes get more intimate as the game goes on. She gets a bit more mischievous and daring, but still keeping her personality on an even keel. The C8 sex scene between them, I could tell, if it was an actual porn movie, would be filled with heated passion. She finally says the three little words to him (which I am
STILL waiting for him to say back to her)
The C10 at the clinic things take a turn with Katie channeling a bit of Carli; she's a bit more mischievous at this point and even more playful and it looks like she's opened herself completely to the MC. She's not the same Katie that started the game, but she evolved into the "girl-next-door" with a bit of a naughty side, but she's also very loving and caring.
The perfect girl in my opinion.
and thanks for the shout-out
Post Edit: Spelling mistakes