There's something I have to get off my chest that's related to some of the chatter going on here.
So I did a normal mode pure run of this game (I don't recommend this) and I noticed something that you may have also noticed on your runs. Kana's dialogue and even behaviors, with very little exception, basically don't change at all throughout. That is, no matter how corrupted she is, she'll have almost entirely the same dialogue on missions and in phone conversations, she'll (almost) always invite Tsukasa for dinner and have the same cheery conversations during mealtimes and dates. She'll always thank Tsukasa if he rescues her from Lawrence's advances and run off with him for a date. And likewise, no matter how pure she is, she'll always lie to Tsukasa about anything that happened between her and Lawrence, and will always acquiesce to Lawrence's harassment without intervention.
This game takes advantage of hidden and unknown information to breed a certain atmosphere. And the biggest unanswered question for me was: How does Kana feel about all this? Her interactions with Tsukasa during exorcisms and after work are clear evidence that they have a lot of trust and love in their relationship, but there's other evidence in the game (obviously) that show that this trust and love perhaps don't extend that far. On the other hand, even in the "high NTR" scenes with Lawrence she clearly has some amount of hatred and disdain for him and what he's doing, and continues to try to nominally be faithful to Tsukasa. Again, she always seems happy and grateful when given the chance to be separated from Lawrence. How are we supposed to interpret her relationship with the two men in her life?
I'd like to call attention to a few scenes in particular. If Kana and Lawrence have had a lot of sex in one day in the daytime, she'll rush home to have more sex... with this man she apparently hates, in her own bedroom. She'll thank Tsukasa for checking up on her (this comes across as genuine gratitude) before ducking back into her room to fuck him for the next two hours. She was apparently in such a rush that she didn't even take off most of her clothes. What are we supposed to make of this? How willing and wanting was she to do this? She pretty much doesn't seek out Lawrence herself in any other situation even given the chance. The other scene I wanted to bring up was one of the "drunk at Lawrence's house" scenes. In the second one, her demeanor comes across as affectionate, even happy. Even given the effect that alcohol can have on one's inhibitions, how much are we supposed to take from this?
Kana is, in many parts of the game, a confident, competent, cheery, and strong-willed woman. She's not the bumbling clueless heroine like in some corruption titles. But this is in contrast to how easily she seems to be swayed by the other two characters. Again, she'll always gladly leave Lawrence for Tsukasa if harassed, but also never make an attempt to get away from Lawrence otherwise. The terms of Lawrence's power/blackmail over Kana is again not made explicit, but one has to imagine that to get away with what he does throughout the game there has to be something else going on.
And after pondering this for a while, I also thought that this character and her circumstances were designed with intention and limited development resources by a couple of developers. So perhaps these contradictions and inconsistencies are more easily explained as oversights or incomplete features rather than having a narrative reason.
So after all this, to conclude:
NTR rots your brain