Rohan is a mangaka in the Jojo world and an Important character to the plot overall. He first appears as an antagonist [much like half the cast] to Koichi and Toshizaku when they go to his house for an autograph. After they try to sneak a peek of the new issue of his manga he uses his stand Heaven's Door to make neither of them able to attack him. Then he reads their memories and in doing so finds out about Josuke, Okuyasu and everyone else in the story so far, but only according to how Koichi sees them. Then he decides to use them as materials for his manga. After using Koichi as his personal "Inspiration" Okuyasu and Josuke find out about where Koichi has been going by following him. They Defeat him and leave him in the hospital for a while.