That’s great. Apparently, haiku written in response to their haiku is also a thing, although I can’t remember the name for it.

I could be wrong here, but I think haiku was born out of the renga, which was a collaborative poem written by two or more people in a call and response sort of fashion.

Basically, one person would write a short poem and another person would answer it with a short poem, and the process would continue. In some traditions, the goal was to have 100 responses (including the original poem).