Ayano’s behaviour is rather consistent not strange at all, she’s an ojousama from a traditional Japanese family, it’s only natural for her to hold a reserved attitude until the male confesses first. To bad she hasn‘t got one so far, only plausible sexual harassment and ever shifting attitudes from Kazuma‘s end.
Kazuma in the novel is a very self-serving and uncaring person, he does what pleases him and he gets what he wants. He has been following Ayano around willingly for so long, he has abandoned Ayano countless times but never actually let anything bad happened to her since the battle aginst Ryuuya, this very fact alone hints some truth in it.
This isn’t obvious in the anime because the anime version of Kazuma isn’t mean to start with, and far from evil, plus Gonzo created quite a few additional KxA love-love moments to please the fans, so when he does something which was supposed to be “unusual” it appears like all very ordinary everyday stuff…
Catherine is just a filler character, if the anime stays faithful to the novel in main plot development, we‘re unlikely to see her again, though Gonzo might change the plot since they have gone through the trouble to re-image Catherine from a sharp woman to a silly girl, and the fight between Kazuma and Genma into a ridiculous onsen, anything can happen in the coming arc…
