Cats would seem to be beloved everywhere, even in pre-modern Japan. And why not, eh? Indeed, who doesn't love a cute cat?
The kigo (season word) here is neko no koi, cat's love. It is a season word for early spring. I don't watch cats enough to know how true it is, but evidently this has long been considered the time of the year when cats are getting it on with each other.
What I like the most or what I enjoy the most about your Haikus are the interesting teachings and explanations you put in your posts about Japan, I enjoy them very much, a hug friend =)