Does anyone know where I can buy the Fox Miko Kon Set? The wiki says I can buy it from the npcs in town, but I don't see it at all. Does anyone know why?

The wiki shows all existing clothing sets, not necessarily from the mirror. Most of the sets are probably from the Nyankoropon from the Shopping Plaza with the Fox Miko Kon Set being one of them. I don't think it's available at the moment but they do bring costumes back occasionally. The Mirror never removes costumes so what you see there is all that will be available unless CS adds more.