The world setting of this drama is that ordinary humans and anthropomorphic animals live together. Except for their appearance, these animals are no different from humans. Bojack (voiced by Will Arnett) is a middle-aged out-of-date star horse. The TV series "Horse" starring him when he was young was all the rage. Now he is an out-of-date star who no one cares about. He lives with the human waste Todd (voiced by Aaron Paul) in a villa in LA. In order to regroup, Bojack decided to publish an autobiography under the urging of his agent and ex-girlfriend Princess Caroline (voiced by Amy Sedaris), hoping to return to the public eye. However, because Bojack was too procrastinating and unwilling to write, the publisher introduced a gunman author Diane (voiced by Alison Brie) to him. Bojack refused many times, and finally, at a party, he met Diane, only to find that she was the girlfriend of his nemesis Mr. Peanut Butter.