Hirohiko Araki casually revealed that a new one-shot featuring Rohan Kishibe will be published in a magazine early next year. Araki mentioned the news when he accepted his Iwate Hometown Special Manga Award on December 19, 2021. Iwate Prefecture’s official YouTube channel posted the video recording of the event today on December 24, 2021.
Source: 6th Iwate Special Award Ceremony
The one-shot is part of the Thus Spoke Kishibe Rohan series, which is a set of short stories, each spanning a single chapter of around 40 to 60 pages and usually organized into disordered “episodes”. They all feature Rohan Kishibe, who frequently witnesses and subsequently narrates the supernatural phenomena around him.
The last chapter of Thus Spoke Kishibe Rohan, titled The Run, released on February 26, 2018. The Run is also getting a live action adaptation which will air in three days on December 27. NHK uploaded a new trailer for the TV drama earlier today.
In regards to the ninth part of JoJo’s Bizarre Adventure, tentatively named JOJOLANDS, Araki stated that aside from the usual difficulties of working on a new arc, everything is more or less prepared. JOJOLANDS was first announced in the September 2021 issue of Ultra Jump, which released on August 19.
Update (December 27, 2021): The one-shot will be published in JOJO magazine, a new magazine dedicated to the franchise releasing on March 19, 2022.