Well, Hazama DID traumatize him when he was a boy and...he hates Hazama/Terumi the most. Revenge for his siblings, especially Saya and the sister (was it...an older Celica?) AND he's the main character; most of the cast wants him for a reason.
From what I've seen in her arcade ending, it shows that she failed and that she's starting to become like her blob husbando. (I think her speech started to become distorted too)