Sheesh, simmah down, people.
This is actually the best thing which could happen for Kazuya. They're already indicating that the date will be exactly what Kazuya expects, and Mizuhara will get bitchslapped by reality. She will learn that one guy actually really cares for her and tries his hardest to support her, and that the other guy she naively rated significantly higher is indeed a jerk, just like Kazuya said. Which consequently proves to Mizuhara that she herself is much less smart than she thinks she is, and Kazuya significantly more. And that she should treat him much more on eye level instead of her lessening, but still noticeable arrogance.
What I still give the show high praise for is that here, the female goddess type lead does NOT fall for the wet noodle male type quickly and for an inconceivable reason, but that he actually needs alot of patience and hard work to turn her around. This is fairly rare and deserves the pain of watching through this.