Syo has a really good gaydar. Like, she can tell if someone is a fellow queer just by looking at them. And she's always correct. She hasn't been wrong. Ever.
(Okay but, like, this is kinda canon. In the game it's stated that she only kills gay guys, AKA, "Pretty Boys". And Syo has called Togami, Chihiro, and Nagito a Pretty Boy. ARE WE NOT GOING TO POINT OUT THE FACT THE GENOCIDER HAS CALLED ALL THREE OF THESE MEN GAY!?!?!?! AND THAT SHE PROBABLY SHIPS ISHIMONDO. KILLER GIRL IS A SHIPPER AND PRACTICALLY COMES OUT FOR THESE MEN!!!! LIKE, SHE'S A FUCKING G O D . HOLY SHIT!!!)