She is turned on by the idea of almost kissing Uihara. Saten has always had a yuri dream or fetish to get into Uiharus panties. This is like sexual overload for her.
Dutchems said: From what I can tell, Uiharu is feeding Saten a (what I would assume is a psychoactive) mushroom with her mouth.
I guess drugs are a pretty big turn on in places where they are heavily outlawed? Or maybe just hard to acquire, I don't know lol.
That isn't a mushroom. It's a Japanese snack shaped like a mushroom. Made out of chocolate and the same thing pocky is made of. Completely forgotten the name of it though.