jojo's bizarre adventure: diamond is unbreakable (ジョジョの奇妙な冒険：ダイヤモンドは砕けない/jojonokimyōnabōken: daiyamondo wa kudakenai) is the 4th story arc of the manga and anime jojo's bizarre adventure created by hirohiko araki. the story follows the adventures of josuke higashikata, koichi hirose, okuyasu nijimura, jotaro kujo and joseph joestar as they try defeating the killer, yoshikage kira.