Part 4: Diamond is Unbreakable

Part 4 of JoJo's Bizarre Adventure, subtitled Diamond is Unbreakable, is preceded by Part 3: Stardust Crusaders and followed by Part 5: Golden Wind. Josuke Higashikata is the main JoJo of this part and Yoshikage Kira serves as the main antagonist. Enemy Stand Users serve as the villainous faction for this part.

This is the second part to incorporate Stands after Part 3, and introduces the Stand Arrow, which is comes more important in the following two parts.

Originally titled JoJo's Bizarre Adventure: Part 4: Jousuke Higashikata, the manga first released in Weekly Shonen Jump in 1992.

In 2007 a non-canon light-novel titled The Book: 4th Another Day was released written by Otsuichi and illustrated by Hirohiko Araki. It served as a sequel to Part 4 that takes place two years after in 1981. It was released to commemorate the series 20th anniversary.

Starting in 2013, the first of the one-shot manga titled Thus Spoke Rohan Kishibe, written by Araki, was released. TSRK is a collection of short side stories featuring the Part 4 character Rohan Kishibe.

Diamond is Unbreakable was adapted into a TV anime as the third season of JoJo's Bizarre Adventure: The Animation in 2016.

Starting in 2017 an anime adaptation of the Thus Spoke Rohan Kishibe series began releasing as OVAs. There are currently four episodes adapted from the nine chapters released.

In June of 2017 a collection of short stories in the Thus Spoke Rohan Kishibe series was released, written by Ballad Kitaguni, Ryo Yoshigami, Yusuke Iba, and Mirei Miyamoto.

In July of 2017 a film adaptation of Part 4 was released. It adapts the first few arcs of Part 4 and ends with a cliffhanger, omitting several characters and plot points.

In 2020 a live-action TV drama adapting four Thus Spoke Rohan Kishibe stories was released for a limited time. It adapted three chapters from the Araki written one-shot manga, and one chapter from the collection of short stories.

The Part 4 manga was officially released in the United States from 2019 - 2021.

Official Description
In 1999 in the town of Morioh, Josuke Higashikata and his friends uncover the mysteries of their small town, fighting fellow Stand Users like themselves, and eventually taking down their town's local killer, Yoshikage Kira.

Plot Summary
The fourth part is set in 1999 in the fictional city of Morioh Japan, and follows Joseph Joestar's illegitimate son, Josuke Higashikata. The story revolves around the mysteries of the small town that Josuke and his friends inhabit, as well as discovering the truth about the Stand Arrow and how it tempts the people of Morioh. Josuke and his friends also track down the illusive murderer, and Stand User, Yoshikage Kira. The story ends at Yoshikage Kira's defeat, and the golden heart of Morioh being preserved.

Characters

 * Josuke Higashikata - Billy Kametz
 * Okuyasu Niijmora - Jalan K. Cassell
 * Koichi Hirose - Zach Aguilar
 * Rohan Kishibe - Vic Mignogna
 * Jotaro Kujo - Mathew Mercer
 * Yoshikage Kira - D.C. Douglass

Stands

 * Crazy Diamond
 * Echoes (ACT1, ACT2, ACT3)
 * The Hand
 * Heaven's Door
 * Love Deluxe
 * Harvest
 * Killer Queen; Sheer Heart Attack; Bites the Dust
 * Aqua Necklace
 * Bad Company
 * Red Hot Chili Pepper
 * The Lock
 * Surface
 * Pearl Jam
 * Achtung Baby
 * Ratt
 * Cinderella
 * Atom Heart Father
 * Boy II Man
 * Earth Wind and Fire
 * Highway Star
 * Stray Cat
 * Superfly
 * Enigma
 * Cheap Trick

Unnamed Stands

 * Nijimura Father's Stand

Songs

 * Crazy Noisy Bizarre Town
 * Crazy Noisy Bizarre Town (EDM Version)
 * Chase
 * Great Days

The Book: JoJo's Bizarre Adventure 4th Another Day
A non-canon light novel written by Otsuichi in 2007 set one year after the events of Part 4. The novel follows four different perspectives, ranging from Koichi Hirose's perspective, the perspective of Takuma Hasumi the main antagonist of the book, Akari, Takuma's mother, and Chiho Futaba who is Takuma's best friend/sister. The book features two original Stands created by Otsuichi, The Book and Memory of a Jet. It is non-canon but it does not conflict with the existing timeline so it very well could be canon.

Thus Spoke Kishibe Rohan (one-shots)
Starting in 2013, Hirohiko Araki began writing several one-shot chapters telling mini side stories from the perspective of Part 4 character Rohan Kishibe. They are canon to the JoJo timeline, as they are written entirely by Araki and fit into the plot.

Chapters for this series go as follows:


 * Episode 16: At a Confessional


 * Episode 2: Mutsu-kabe Hill
 * Episode 5: Millionaire Village
 * Episode 6: Poaching Seashore
 * Kishibe Rohan Meets Gucci
 * Episode 4: The Harvest Moon
 * Episode 7: A Rainy Monday
 * Episode 8: Deoxyribonucleic Acid
 * Episode 9: The Run

The chapters are listed as "episodes" and release out of order. Because the highest numerical value for the chapters goes up to 16, it is implied that there may be at the very least 8 more chapters to be released that take place before At a Confessional. The only one of these chapters that is not confirmed to be canon to the JoJo timeline is Kishibe Rohan Meets Gucci.

Rohan at the Louvre
Another addition to the Rohan saga, this is a non-canon story that acts as promotion for Araki's artwork being shown at the Louvre in Paris. It tells the story of Rohan visiting this art museum and discovering some dark secrets about some of the contents in this facility. It is confirmed to be non-canon because it conflicts with the information already provided to us in the official JoJo lore.

Thus Spoke Rohan Kishibe (OVA)
Starting in 2016 a couple of the one-shot chapters for TSKR began being adapted into an OVA by David Productions.

Trivia

 * In this part the Stand Arrows are introduced. It is explained that this is how DIO awakened his Stand, and we know this because Joseph uses Hermit Purple to uncover an image of Enya holding the Stand Arrows.
 * The Stand Arrow is added into the background of a scene in the Stardust Crusaders anime so that this explanation makes more sense.
 * We are shown three different Stand Arrows existing in this world in this part and the one before. The one that belonged to the Nijimura brothers, the one that belonged to Yoshiro Kira, and the one that was in the hands of Enya the Hag.