Modern Social issues in Kappa

"Kappa" mirrors many contrasting aspects of our society, its really interesting and gets the reader to think about our society as a whole. One aspect that stood out the most to me is regarding capital punishment. In Kappaland the capital punishment method is electric chair, but in most cases they use mental abuse to kill the target by forcing them into suicide. This instantly reminded me how many teen suicides are due to mental abuse and bullying. I feel like the author is trying to bring up and mock bullying/mental-abuse caused suicides in our society, how people push others over the edge through bullying and mental stress but walk away like nothing happened when they caused somebody to end their own life. But clearly such actions such as bullying and mental abuse is deliberate intention to kill someone.

Question: Tok's spirit talks about Matsuo Basho's haiku "The old pond", why does the Kappa mention this particular Japanese haiku? What's the significance? Is there a message from the author?