Diamond is Unbreakable - Chapter 5 
Anjuro is hiding near Josuke's house and trying to find a way to get his Stand out of the whiskey bottle. He notices Josuke's grandfather, Ryohei, entering the house. He recognizes him as the same policeman who once arrested him. Aqua Necklace expects Ryohei would want a drink after his night shift and disguises the whiskey bottle it is contained in as cognac. Josuke and Ryohei learn that a serial killer, who has murdered seven people, is running loose.
Jotaro arrives at the house, and after Josuke greets him, he notices that his grandfather has drunk the contents of the whiskey bottle and been attacked by Aqua Necklace. Josuke pummels Aqua Necklace with his Stand and then heals his grandfather's injuries, but to his confusion, Ryohei does not get up. Jotaro tells him that his grandfather is already dead, and explains that there is no Stand with the power to revive the dead. Josuke vows to take revenge on Anjuro and protect Morioh in the place of his grandfather.