According to Michael, Human Resources Manager Toby Flenderson is "everything that is wrong with the paper industry." (The Convention) Michael openly despises Toby because he is required to enforce the corporate rules that Michael so dearly loves to break. Michael's long-standing goal is to get rid of Toby forever, and he is overjoyed when Toby leaves Dunder Mifflin to go to Costa Rica in Goodbye, Toby.
Michael even throws a party to celebrate, but Toby eventually returns and their battle continues. It is unknown why Michael truly hates Toby so much.