Filipis Btw I red your review man. It seems that you really liked this game because of wholesome love story ending. They probably ripped off that ending from "The Student Council President is My Sex Friend (Atelier Sakura)", I recommend you to check that one out (I personally hate that game but it fits to your taste).
Zack also probably ripped off from that game as well, since that games character is also equally shit human being as Zack, but magically transforms to sincere human being after he fucks like rabbit with nymphomaniac FMC.