I retract myself, Kazuya isn't the victim of those five witches, but their punishment. He somehow made all of them go crazy for him and suffer it in different ways:
Mami: her ego was destroyed and tried to recover it failing at the point that even his brother made her mad about it (her ego, not Kazuya).
Chizuru: she's doing shady things like toying with a dude while rejecting she's in love with him. The worst part is she doesn't look ashamed of lying to her grandmother in her last moments.
Ruka: she's the one suffering the worst part because she's forced by the author to debase herself for a dude who she knows doesn't love her.
Sumi: she's watching how the guy she loves has an emotional chaos because he's in love with her only friend.
Mini: she somehow tries to avoid her feelings by being a wingman, but deeply she wishes for a man this crazy about her, of course she hides it, but in the end she already fell for Kazuya.
He's not the victim, but the executioner, you can't fail a task so successfully by accident.
This story isn't a rom com, but a psychologic horror story where Kazuya works perfectly as both the victim and executioner. If you stop seeing it as romance, you can find the horror behind the jokes and comedic nonsense... and that is my headcanon.
Mami: her ego was destroyed and tried to recover it failing at the point that even his brother made her mad about it (her ego, not Kazuya).
Chizuru: she's doing shady things like toying with a dude while rejecting she's in love with him. The worst part is she doesn't look ashamed of lying to her grandmother in her last moments.
Ruka: she's the one suffering the worst part because she's forced by the author to debase herself for a dude who she knows doesn't love her.
Sumi: she's watching how the guy she loves has an emotional chaos because he's in love with her only friend.
Mini: she somehow tries to avoid her feelings by being a wingman, but deeply she wishes for a man this crazy about her, of course she hides it, but in the end she already fell for Kazuya.
He's not the victim, but the executioner, you can't fail a task so successfully by accident.
This story isn't a rom com, but a psychologic horror story where Kazuya works perfectly as both the victim and executioner. If you stop seeing it as romance, you can find the horror behind the jokes and comedic nonsense... and that is my headcanon.