If Kouta exhibit a passive aura that NTRs and makes the girls fall in love with him
Then Purple devil exhibits the aura that makes every single person around her dumb as rocks including her little sister
I've just realized, so the reason why the date went off perfectly last chapter is because he isn't thinking. He even told to himself a chapter before that that he practiced so much that he can do things without even thinking at this point.
This kid gave his lowest effort to a date and somehow the girl who clearly hated him is just down with it. The ability to make Yanderes just by existing is truly scary.
Edit: Recorrection "Sheer Dumbassery"
Disillusionment is going to hit hard for all these ladies at one point. But then again, all of them saw his pathetic side yet somehow they're still infatuated. How?
New blackmail material from the purple cat girl, she's at the background from the last chapter I doubt she won't miss her chance recording his "confession"
The teacher is as crazy as the sister, she's aware he's dating someone since the whole guild knows about the relationship. What's worse, she's aware he's a middle schooler