JoJo no Kimyou na Bouken: Diamond wa Kudakenai adapts the fourth part of the JoJo no Kimyou na Bouken manga series. It's the year 1999, 11 years after Jotaro Kujo's desperate fight against DIO in Egypt. Jotaro meets with Josuke Higashikata, the illegitimate son of his grandfathe…