First introduced in JoJo's Bizarre Adventure Part 4: Diamond is Unbreakable, the arrogant manga artist Rohan Kishibe has become a breakout character, starring in his own spinoff manga and short stories, OVAs, and even a live-action miniseries. In JoJo, Rohan is a 20-year-old manga artist who writes a very popular shonen series called Pink Dark Boy.
While JoJo's audience isn't told many details regarding what Pink Dark Boy is about, various clues throughout the franchise give a bit more information about Rohan's manga.
Pink Dark Boy is a Long-Runner
In the spinoff manga Rohan at the Louvre, Rohan is shown to begin working on Pink Dark Boy in 1996, three years before the events of Diamond is Unbreakable, meaning he was 17 when he started writing the manga. Although not all of them are considered canon, several spinoff materials establish that Pink Dark Boy has eight parts, just as the JoJo manga currently does. These spinoffs usually take place some years after Diamond is Unbreakable as well. Despite his manga's popularity, Rohan mentions that it has never been translated into English because "Americans have bad taste." The comment is likely a sarcastic reference to the fact that the JoJo manga had no English translation when Part 4 was written.
Both live-action adaptations of the JoJo franchise have shown Pink Dark Boy to have many volumes. In the Diamond is Unbreakable movie, Koichi Hirose owns 20 volumes of the manga, while in the Thus Spoke Kishibe Rohan miniseries, Volume 81 is seen. Pink Dark Boy began as a weekly series, published in Weekly Shonen Jump, but Rohan's injury from Josuke Higashikata switches it to monthly releases. Its original weekly release would account for a large number of chapters it is shown to have.
Rohan's Manga Is a Horror Story
After Rohan's introduction, Koichi mentions that Pink Dark Boy is a horror manga filled with suspenseful and grotesque scenes. Not much later, Rohan kills and licks a spider, claiming that he wants to know how its insides taste as "research" for his manga -- which could confirm the grotesque content Koichi claims the manga has. In Thus Spoke Kishibe Rohan, Rohan also investigates a rumored supernatural occurrence as part of his research, suggesting that Pink Dark Boy might also contain paranormal happenings.
Despite its horror focus, Pink Dark Boy is known for its realism. Koichi says that the series has realistic characters, and the reason for all of Rohan's research is that he believes manga is best when based on real-life experience. Rohan also travels often for his work, including a week-long stay in Venice, suggesting that much like JoJo, Pink Dark Boy takes place in various locations worldwide. According to the non-canon Thus Spoke Kishibi Rohan prose story collection, the manga is an anthology made up of many interconnecting stories.
The Manga Becomes Rohan's Stand
Rohan's Stand, Heaven's Door, didn't manifest a physical form when initially introduced. Instead, it allowed him to turn others into books that he can read and write in. Rohan can read and alter information about those affected by Heaven's Door and write commands they must follow with this ability.
Heaven's Door acquires a humanoid form in later appearances -- one that happens to look exactly like the apparent main character of Pink Dark Boy, though seemingly with a different color scheme. While humanoid, both the Stand and the character have an inhuman aspect to their appearance, further supporting the idea that Rohan's manga may contain supernatural elements. A Stand's appearance and abilities are generally strongly influenced by its user's psyche, so Heaven's Door appearing as his manga character proves just how important Pink Dark Boy truly is to Rohan.
