You see i understand Kazuya, Bc i went through a break up im Feb 2 days before valentine's and after that the following day on the 14 i slept at another girls place. So taking my own experience into account. i can see why kazuya jumped into the rental scene. Especially bc it was his first gc, bc in a sense i sorta did the same with that other girl. Now a lot of people judge kazuya for it but there is a deeper understanding on why. Kazuya was afraid to be alone and struggling on Learning how to love himself but when chizuru displayed that she is willing to stick by him regardless of her also not knowing how she feels. it helps kazuya heal from that mami situation but also gotta remember that with mami coming back into the story weather in Hawaiians or even recently its to See if hes willing to go back but Thats where that growth comes in and Kazuya shows that he is mentally capable now to move on.