Josuke apparently developed his Stand off-screen in the events of Part 3, when Jotaro Kujo and company traveled to Egypt to kill DIO. As a result of DIO being pierced by the Stand-creating Arrow, Josuke, possessing the Joestar Bloodline that runs in Jonathan's body, develops a Stand, but suffers a fever not unlike that of his half-sister Holy. He is then saved by a then-high school student with a pompadour, who throws his coat under his mother's car in order to allow their car to plow safely through the snow. This then inspires Josuke's admiration for the man with the pompadour.
On an April afternoon in the year of 1999, Josuke is confronted by Jotaro, the protagonist of Stardust Crusaders. The man then reveals himself to be Josuke's nephew. Josuke was in fact the product of an illegitimate affair between Joseph Joestar and the Japanese Tomoko Higashikata. Josuke did not seem surprised by the news; he informed Jotaro that he had long since accepted the circumstances of his birth. However, Jotaro makes the unfortunate mistake of insulting Josuke's hairstyle, causing him to attack Jotaro in a fit of rage. Jotaro takes note of his Stand Crazy Diamond, which possesses speed and power enough to match that of Star Platinum. He proceeds to tell Josuke about the second reason he had come to Morioh: an evil killer named Angelo is on the loose, and he possesses a Stand, to make things worse. Jotaro warns Josuke (and Koichi Hirose, who happens to be nearby) to watch out for any signs of the man. He then goes to Budogaoka where he joins the first year class 1-B along with Koichi.
|“||You can say that the human species destroy as they live.. but your power is kinder than anything else in this world.||”|
—Jotaro Kujo, Josuke Higashikata Meets Angelo!
On his way home, Josuke encounters a supermarket robbery and rescues the woman being held hostage. It turns out the robber was under the influence of Angelo and his water-based Stand Aqua Necklace. Angered at Josuke's interference, Angelo swears to find Josuke's home and kill his family. The next day, Josuke manages to capture him once, but Angelo craftily changes his Stand to mimic a bottle of brandy and tricks Josuke's grandfather Ryohei Higashikata into taking a drink. Ryohei dies, and even the abilities of Crazy Diamond could not revive him. Josuke decides to protect Morioh in his grandfather's place. He and Jotaro set up camp within the Higashikata household, drinking and eating only bottled water and canned food for three days. When it begins to rain, Angelo carries his Stand in on the raindrops and began to boil water inside the house. Soon there is steam everywhere, and the threat of Aqua Necklace is imminent. However Josuke purposefully allows Aqua Necklace into his body, having swallowed shredded pieces of a rubber glove that he later restores to trap the enemy Stand. Approaching Anjuro, Josuke and Jotaro learn about a mysterious Stand user who used an Arrow to awaken his Stand, then Josuke fuses Angelo's body together with a rock, creating a local landmark.
One day, Josuke and Koichi notices a suspicious house on their way to school, seemingly wrecked and abandoned. The house turns out to be the residence of the brothers Okuyasu and Keicho Nijimura, two Stand users. A fight ensues when Keicho shoots Koichi with an Arrow, and although Josuke rapidly defeats Okuyasu, Keicho is a tougher opponent. Nonetheless, Josuke manages to uses Keicho's Bad Company against him and wins. Josuke and Koichi then discover Nijimura's Father in the attic, now a dumb monster, which Keicho reveals is seeking to kill in order to end his suffering. Josuke manages to prove that the father still has sentience in him and that there may be a cure for his condition. However, the three are suddenly attacked by Red Hot Chili Pepper, and Keicho is killed taking a blow for Okuyasu. Red Hot Chili Pepper then escapes with the Stand Bow and Arrow.
When Okuyasu and Koichi fall victim to Tamami's Stand, he saves them by revealing the cat Koichi ran over was a toy and heals Tamami's tooth. He is surprised when he sees Tamami handing Koichi his bag.
Hearing information from Tamami Kobayashi, Josuke and Koichi investigate a 3rd year student from their high school, Toshikazu Hazamada. Hazamada's Stand Surface takes on the appearance of Josuke and sets off to assassinate Kujo Jotaro. With Koichi's help, the two manages to meet Jotaro before Hazamada and the false Josuke. While Surface briefly succeeded in gaining control of Josuke's body, Hazamada is attacked by two thugs he angered earlier, and soon knocked out by Josuke's fists. Josuke also destroys the wooden body Surface was using.
After Yukako Yamagishi's intense declaration of love, Koichi confides his troubles with his friends Josuke and Okuyasu. They advise that in order to cause Yukako to lose interest in him, he has to convince her he is not worth her time. Josuke then tries spreading the rumor that Koichi is a petty thief and a cheat. Unfortunately, this causes the exact opposite of the intended effect, and Koichi is kidnapped by Yukako and taken to a mansion on the far end of Morioh. When Koichi is nowhere to be found the following morning, Josuke assumes something is wrong. He and Okuyasu track Koichi's desperate phone call and arrive just in time to witness him defeating Yukako with his new and improved Stand.
One afternoon, Okuyasu and Josuke discover a new restaurant. Upon Okuyasu's insistence, the two head inside. The head chef and waiter Tonio Trussardi greets them, promising a very special Italian course to cure Okuyasu's sleep deprivation and other ailments. Josuke's suspicions grow as Okuyasu dish cause various strange phenomenons on his body, and storms into the kitchen to confront Tonio. However Tonio is revealed to be harmless and only cross with Josuke for entering the kitchen without washing his hands. Once the misunderstanding is cleared up, Josuke and Okuyasu introduce themselves to Tonio as fellow Stand users. Though, Josuke is forced to clean Tonio's entire kitchen from top to bottom because he broke in without respecting proper hygiene.
One evening, the Stand Red Hot Chili Pepper appears from Josuke's television set and looks for a fight. Although Crazy Diamond is seemingly stronger and faster, Red Hot Chili Pepper manages to overpower it briefly and flees. The next day, Josuke, Koichi and Okuyasu learn from Jotaro that Josuke's father Joseph will come root out the Stand user, but Red Hot Chili Pepper eavesdrop on them and escapes.
At the harbour, while Jotaro and Okuyasu go meet Joseph on his boat to bodyguard him, Josuke encounters Red Hot Chili Pepper's user Akira Otoishi. Although Red Hot Chili Pepper is the most powerful, Josuke manages to trap it in a tire then make it dissolve its electricity in the ocean, defeating it.
Afterward, although Akira manages to approach Joseph, he is defeated by Okuyasu, and Josuke meets his estranged father.
Josuke and Joseph's relationship is awkward, and Josuke initially wants Joseph to leave Morioh as soon as possible. They are distracted when they meet an invisible baby, and have to take care of it. When the baby falls into a pond, Joseph slits his wrist and the blood allows Josuke to spot the invisible baby before she can drown, forcing Josuke's respect.
He was upset when he found out about all the money Joseph spent on baby supplies.
One day, Josuke and Okuyasu spot Koichi enters the house of a famous mangaka named Rohan Kishibe. Suspicious because Koichi is wounded, both break into the house but Rohan's Heaven's Door allows him to transform anyone who sees his artwork into a powerless book. However Rohan makes the mistake of insulting Josuke's hairstyle, causing him to be literally blind with rage and become immune to Heaven's Door, and Josuke sends Rohan to the hospital.
The origin of Josuke's hairstyle is revealed. One day when he was ill, he had to be taken to the hospital but his mother's car was blocked in the middle of nowhere. A teenager with a pompadour helped restart the engine and saved Josuke, and to this day, Josuke takes after his savior's hairstyle.
Jotaro enlists Josuke on a rat hunt, as Akira Otoishi used the Arrow on a rat, which survived. Seeking to stop a potential swarm of rat Stand users, Jotaro and Josuke hunt what is revealed to be two rats, which can melt anyone with darts. One rat is killed rapidly but the second nearly kills Jotaro before Josuke can snipe it.
One day, Josuke notices that his bank account is nearly empty because he spent his money frivolously. Desperate for money, he and Okuyasu meet the Stand user Shigekiyo Yangu, a middle schooler, whose swarm-like Harvest can go look for anything. Although Josuke and Okuyasu devise successful ploys to become rich thanks to Harvest, Shigekiyo's greed causes them to fight over 5,000,000 yen. Shigekiyo is eventually distracted by Josuke destroying the prize and foolishly sends Harvest away, leaving him defenseless to be beaten. The three eventually reconcile.
One day, Josuke sees a disintegrating Harvest giving him a jacket button, although Shigekiyo was alive and well not five minutes after. The ghost Reimi Sugimoto confirms that the mysterious killer who has been preying on the women of Morioh is responsible for Shigekiyo's death, and every ally of Josuke begin a hunt for the killer. Josuke is eventually called by Koichi, who has encountered the killer's Stand, and Josuke arrives in time to corner the murderer, Yoshikage Kira. However Kira manages to flee, and change his face by using the local beautician Aya Tsuji's power.
One day, Josuke and Okuyasu meet the self-proclaimed alien Nu Mikitakazo Nshi. Although skeptical at first, Josuke becomes convinced that Nu is an alien because he cannot see Stands despite having shape-shifting powers. Since his mother froze his bank account, Josuke is again desperate for money and devises another plan with Nu's cooperation. Josuke sets up a game of cee-lo with Rohan in which the dice are secretly Nu, but Nu's unfamiliarity with the rules almost gets Josuke caught. The game finishes with Rohan's house burning while Josuke gets away, and the grudge between the two increases.
The next day, Josuke sees Nu with his mother, but while Mikitata insists he's hypnotized her, the mother also mentions that Mikitaka believes he's an alien, confusing Josuke.
One day, Josuke meets Rohan in the bus. Rohan still has a grudge, but when the Stand Highway Star traps Rohan in a tunnel, and almost traps Josuke, Rohan frees Josuke at his expenses, and Josuke must now find Highway Star's user while being pursued by it. Calling Koichi for help, Josuke manages to ride Rohan's motorcycle from the tunnel to the hospital where Yuya Fungami is being hospitalized. Josuke beats him up and frees Rohan.
One day, Josuke, Okuyasu and Mikitaka discover a disconnected electric tower in which lives Toyohiro Kanedaichi, a man who lives in autarcy inside the tower. Josuke is trapped inside the tower, revealed to be the Stand Super Fly, but Josuke cooperates with Mikitaka to battle Toyohiro, who eventually apologizes and reveals that Koichi was attacked by another Stand user.
Josuke enlists the help of Yuya in order to investigate how Koichi disappeared. Both meet Terunosuke Miyamoto, the user of Enigma, a Stand which imprisons people in paper. While Josuke is trapped, Yuya manages to save him as well as Koichi, and Terunosuke is fused to paper and becomes a book. Josuke then proceeds to imprison him in the library.
Rohan manages to discover a serious lead, as the young Hayato Kawajiri suspiciously spies on his father Kosaku. The group organizes a meeting in order to interrogate Hayato, but Hayato who has discovered that his father Kosaku is the murderer, calls Josuke ahead and makes Kira reveal his name while Josuke is listening.
A fight ensues between Kira, Josuke and Okuyasu, but Okuyasu is fatally wounded by the combination of Killer Queen and Stray Cat's powers. While Josuke heals Okuyasu, the latter remains unconscious while Josuke is retreating inside a house. Kira attacks him from outside with explosive bubbles, but Josuke manages to discover that Yoshihiro Kira was helping Yoshikage, and makes Kira inadvertently kill his father. Kira is then wounded by a projectile, and a close-quarter fight ensues between Crazy Diamond and Killer Queen. Crazy Diamond is almost defeated, but Okuyasu manages to teleport Stray Cat away from Killer Queen, allowing Josuke to bypass its defense and pummel Kira into the main street, where Jotaro, Koichi and Rohan were waiting.
Kira is surrounded and wounded, but still determined. When a doctor approaches him, Kira almost activates his time loop, however Koichi and Jotaro manage to take him down, and Kira is accidentally run over by an ambulance.
Now that Morioh is safe from evil Stand users, Jotaro and Joseph departs from the town, and Josuke sees them off, saluting them on last time. Josuke however manages to steal Joseph's wallet as his allowance for all these years.
He is last seen talking with Okuyasu and Koichi about a rumor the former heard and decided to go investigate that rumor.
The information below derives from a Light Novel not written by Araki. As such, it may or may not be considered canon.)
Josuke helps the stand users of Morioh to find the killer of Hanae Orikasa. During the investigation Josuke's mother is injured, leading Josuke to confront Takuma Hasumi, the killer. Takuma finds out that Josuke was saved by a student with a pompadour in his past and tries to use it against him, but this just upsets Josuke more. Even retaining serious injuries from The Book, Josuke manages to defeat Takuma, who ends up falling from the roof of the library against Josuke's will.
Josuke makes a nonspeaking cameo in this one-shot. He heard Rohan's story about Nanase Kishibe with Koichi and Okuyasu before the mangaka decided to investigate Nizaemon Yamamura's painting "Under the Moon".
Josuke makes a cameo appearance in the ending when Rohan talks to Koichi and Okuyasu. Only the back of his head and torso is visible in the shot however.