Cats in Japan?

We watched an interesting documentary on TV tonight about English history. It was followed by a documentary about Japanese people and their love of cats. This puzzled me.

I like cats, not only our own two cats Malin and Totte. Still, dogs are always better.

In Japan, they have the biggest population of the best dog breed in the world, their national treasure, the Shiba. Why would they need to love cats so much that a documentary is made by it? There are Shibas to love.