Both Rupert the fox and William the cat were orphaned earlier in their lives and rescued by the International Primate rescue centre as infants. While they were raised with volunteers, they wound up spending time with each other. Pretty soon they became fast friends.
Rupert was later socialized with a female Fennec fox named Roxy but still makes time to socialize with William. Now that we can see how a cat and a fox can become friends, perhaps there’s still hope that people can became friends too regardless of their differences. Then again, that probably won’t happen, which shows that animals are smarter than most human beings on the planet.