One-shot series stars Diamond is Unbreakable character

Warner Brothers Anime announced on Saturday that Hirohiko Araki's Kishibe Rohan wa Ugokanai ("Rohan Kishibe Does Not Move" or "Thus Spoke Kishibe Rohan") manga will get an original anime DVD (OAD) that will be distributed to customers who buy all 13 DVD or Blu-ray Disc volumes of the JoJo's Bizarre Adventure: Diamond Is Unbreakable anime. The first DVD and Blu-ray Disc will include the first three episodes of the anime and ship on June 22 in Japan, and the 13th and final DVD and Blu-ray will ship on June 28, 2017. The OAD will not be available on Blu-ray.

Kishibe Rohan wa Ugokanai is a series of one-shots starring the Jojo's Bizarre Adventure: Diamond is Unbreakable character Rohan Kishibe, who is also Araki's fictional alter ego. Shueisha published a compiled book volume of the different Kishibe Rohan wa Ugokanai stories in November 2013. Shueisha's Jump Square magazine published the most recent one-shot, "Episode #07 Getsuyōbi - Tenkiame" (Monday - Sun Shower), in December 2015.

The JoJo's Bizarre Adventure: Diamond Is Unbreakable anime premiered on April 1 and Crunchyroll and Viz Media are streaming the series.

Source: Comic Natalie

Update: Rather than including the OAD with any one volume, the OAD will be distributed to customers who buy all 13 DVD or Blu-ray Disc volumes. Thanks, Sakaki.