How many volumes and episodes are in Fruits Basket by Natsuki Takay?

There are 23 volumes in total by Natsuki Takaya, you should most definitely read the manga, it is much, much better than the anime.

The anime has 26 episodes.

The manga has 136 chapters.

So yes, there is a volume 20. There is an episode 20. And there is a chapter 20.