@Richman
So for this arc, Chizuru knew her grandma was dying for a while, and Kazuya had asked her a number of times to break the news that they weren't dating to her so that she didn't have any regrets, but Chizuru kept refusing on the grounds that she didn't want to hurt her grandma with that sad kind of truth. Basically, this is/was her last chance to break the news.
As for their relationship, Kazuya has admitted to liking Chizuru and even said to her grandma that even if they weren't dating, he'd stick by her side no matter what. Chizuru's stance on the whole thing, however, is that she "doesn't
not like him" and even denies that he has feelings for her since they're only bounded by a contract. Yaemori (new girl, not part of the harem, ultimate wingman for Kazuya) pointed out that Kazuya wouldn't have gone as far as to get a Kickstarter going, raised tons of money and got a professional crew together to shoot her movie if he didn't have any sort of romantic feelings for her. So in short, Chizuru's in denial of Kazuya's feelings for her, but why is that, we still don't know.
Hope that helps.