However, one day as Giorno was walking home, he came upon a man covered in blood lying in a patch of tall grass. After discovering the injured man, other men approached Giorno, asking him if he knew where the man had gone. Giorno lied to the men, feeling that the injured man was the same as him, and subconsciously activated his stand, Gold Experience, to mask the man's presence by causing the grass to grow tall. Around two months later, the man showed himself to Giorno again and tells Giorno that he would never forget what had been done for him. Things soon turn brighter for Giorno: his father stopped beating him and he became popular among kids his own age. It turned out that the man was a gangster who quietly watched over Giorno from the shadows. To Giorno, this was the first time someone else had treated him like a human being and showed him respect. The trust that Giorno should have learned from his father was instead taught to him by others, and ever since he no longer had the scared look in his eyes. He subsequently forges a dream to become a "cool gangster" like the man who had helped him.
In March 29 2001, Giorno is 15 years old and operates as a petty thief. Koichi Hirose meets Giorno showing off his famous ear-canal trick in which he stuffs his entire ear into his ear canal. Giorno offers Koichi a ride as an illegal taxi, but in fact steals his luggage and drives away. However Koichi uses Echoes's Three Freeze to increase the weight of the tires. Giorno doesn't let this affect his plans and runs away, after using Gold Experience to turn Koichi's luggage into a frog.
Giorno then meets up with Leaky-eye Luka, who demands protection money from him. Giorno says he has no money, but Luka, who is unconvinced, takes Giorno's wallet and reveals a picture of Dio Brando. Luka becomes increasingly violent while Giorno insists that he has no money. Suddenly the frog, made of Koichi's luggage, returns and begins climbing up Giorno's pants. Upon seeing the frog, Luka orders him to kill it, but Giorno refuses. Giorno's refusal enrages Luka, who smashes the frog with his shovel against Giorno's suggestions, but the side effects of Gold Experience manifest and cause the attack to rebound upon and kill him from severe head trauma.
Giorno then spends the money stolen from Koichi, but the two meet again, forcing Giorno to reveal his stand and escape a second time. Soon, problems arise for Giorno as news of Luka's death spreads, and Bruno Bucciarati visits him on the funicular to interrogate him. Bucciarati's interrogation eventually turns violent, forcing Giorno to openly fight. Giorno manages to gain the upper hand, but doesn't deal the finishing blow as he senses that Bucciarati is a good man. Both develop a mutual respect, and upon Giorno revealing his dream to become a "Gangstar" who will defend the innocent, Bruno agrees to help him infiltrate the most powerful gang of Naples, Passione.
Giorno meets the Passione lieutnant Polpo in prison, who gives him a lighter and tells him to keep it lit for 24 hours in order to join Passione. Giorno manages to get out of prison, go to his student room, and avoid Koichi while keeping his lighter lit, but a janitor accidentally splashes the lighter and extinguishes it. As Giorno tries to figure out what to do, the janitor relights the lighter for him and Polpo's Stand Black Sabbath appears. It attacks the janitor for having re-lit the lighter, ultimately killing him by stabbing his spirit with the Arrow. The Stand then turns its attention to Giorno, who fights back with Gold Experience. Thanks to Koichi's help and counsel, Giorno manages to destroy Black Sabbath. The next day, Giorno meets Polpo again, who accepts him within Passione, hoping to use Giorno as another tool. However, in retaliation for Polpo killing the janitor, Giorno transforms a gun into a banana, leading to Polpo killing himself when he tries to eat the banana.
Giorno then becomes the newest member of Bucciarati's Gang. When brought to meet the rest of the members, he is pressured into drinking a cup of "tea" heavily mixed with Leone Abbachio's urine. He earns their acceptance by doing so, having turned his teeth into jellyfish made of 98% water which absorbed all of the water molecules.
After Polpo's death, the seat of Passione lieutnant becomes available. Bucciarati takes the group on a boat to Capri Island to retrieve Polpo's hidden fortune of 6 billion yen in order to court the Passione higher-ups and get Polpo's position. During the trip, the group faces Mario Zucchero, another Passione member looking for the treasure, and his mysterious Stand. Although Giorno's teammates are disappearing one by one, Giorno manages to deduces that everyone is alive. Before the distrustful Abbacchio, Giorno allows himself to be captured by the enemy Stand. A fly transformed froom Narancia's shoe enables Abbacchio and Bucciarati to track the captured members and figure out the secret behind the enemy Stand and defeat it and its user.
Upon discovering that their would-be assassin has a partner who ran ahead to Capri Island, Giorno and Mista go ahead of the rest on an inner-tube-turned-fish to clear the way, in which Giorno keeps track of Mista's movements and Mista encounters Sale. After Sale's defeat, the group encounter a capo named Pericolo, who has come at Bucciarati's request to take the money and subsequently raise Bucciarati to lieutnant rank. They then receive their first mission: to protect Trish Una, the Boss' daughter, from the traitors seeking to capture her in hope of getting information on the Boss and using her as leverage against him.
Hiding in the countryside
Giorno's group must now bodyguard Trish Una, the Boss' daughter, until the traitors are killed. However, not one day after, Narancia is discovered by Formaggio, a member of the assassination squad La Squadra di Esecuzione. While Narancia manages to kill Formaggio, the group's hideout is practically discovered. Giorno correctly predicts that the Boss will issue new orders immediately.
Ride to Florence
Bucciarati's Gang is told via computer that they have to retrieve a key in Pompei in order to secure an unknown vehicle. In Pompei, Giorno, Abbacchio and Pannacotta Fugo fight Illuso, also an assassin. Giorno retrieves the key, but Abbacchio and Fugo are imprisoned in the mirror world created by Illso's Man in the Mirror. Using Fugo's Stand Purple Haze to infect himself then infect Illuso, Giorno saves himself by creating antibodies.
On the key are engraved the Boss' next orders: Bucciarati must now to go to Napoli Station then hitch a train ride to Venice. While the gang meets the turtle Coco Jumbo which can act as a shelter and hiding spot for everyone, they are pursued by two assassins.
Inside the train, Bucciarati's Gang is attacked by the team Pesci and Prosciutto, and suddenly everyone grows old. Before succumbing to the forced aging, Giorno still works out how Prosciutto's The Grateful Dead functions and its weaknesses. Mista and Bruno would use that knowledge to defeat both Prosciutto and Pesci. However during the battle, Pesci stopped the train, and the gang is now immobilized.
On the roads
Still having to go to Venice, Bucciarati's Gang first try to hitch a ride, but Mista accidentally knocks out the driver, forcing the gang to change their plan again.
In a parking lot, Giorno impresses everyone a second time by using his power to change several cars into masses of frogs and give the illusion that many cars were stolen so that the car Bucciarati actually steals will be harder to track.
Meanwhile another assassin, Melone, used his Stand Baby Face to track Bruno and neutralize both him and Trish inside the turtle. The autonomous Stand, blocked by Giorno, is ordered to kill him. At first, Baby Face has the advantage since it removed Giorno's throat, but this is when Giorno realizes that he can create body parts and attach them to people. That gives him the upper hand allowing him to win against Baby Face without the help of the others. Afterward, Giorno sends a venomous snake made out of Baby Face to Melone, who is bitten and presumably dies.
Bruno receives new orders from the Boss, who tells him to retrieve an unknown item in Venice. Giorno and Mista are assigned to retrieve it while the rest of the group will enter Venice by boat. However, the assassin Ghiaccio attacks both of them and a race toward the item begins. Unfortunately, Ghiaccio's ice power White Album is practically immune to Gold Experience and Sex Pistols. Making the mistake of underestimating Ghiaccio, Giorno is emprisoned by ice while his car is sinking in the sea, and despairs to survive this encounter. Yet, Mista manages to stay calm and cancels Ghiaccio's power, freeing Giorno, and carries on the fight, discovering a weak point in Ghiaccio's armor. In the ensuing shootout, Mista is still overpowered by Ghiaccio, but Giorno manages to help him and finally save Mista as his head is hit by a bullet, then finishes Ghiaccio off by impaling his throat into a metal pole.
Giorno and Mista retrieve a disk which contains the Boss's last orders and are ordered to bring Trish to the San Giorgio Maggiore basilisk. Giorno, eager to find the Boss' identity, gives Bruno a living brooch in order to track the Boss. Unexpectedly, the Boss wanted to kill Trish, and Bruno openly revolts and fights the Boss. Alas, Bruno is no match for the Boss' Stand King Crimson. Giorno notices that something is wrong and intervenes rapidly enough to save Trish, and heal Bruno, who resurrects. Bruno and Giorno announce that they openly rebelled against the Boss, and though many are scared, everyone but Fugo follows Bruno.
Finding the Boss' Identity
Clash and Talking Head
Still in Venice, Bucciarati's Gang debate what to do. Trish eventually informs them that the Boss met her mother in the island of Sardegna, giving the group a solid lead. At the same time, Passione operatives Tiziano and Squalo stealthily attack the group. Narancia is forced to constantly lie because of Tiziano's Talking Head, but Giorno soon suspects that they are under attack. While the shark like Clash nearly kills him, Giorno manages to counsel Narancia to go after the Stand users and Narancia manages to kill both, using a spare tongue Giorno gave him to lure them out.
Flight to Sardegna
With the defeat of Squalo and Tizziano, the group decides to use the chance they have and leave Venice by plane. However, while attempting to steal a jet from a nearby army airport, they are confronted by a mysterious man. Mista ends up killing the man after several warnings to back away, but Giorno is suspicious.
In the plane, Giorno's suspicions are confirmed when the Stand Notorious B.I.G. attacks the group. The Stand proves invulnerable, severely wounding both Narancia and Mista while Giorno cuts off his hands and throws them out of the plane in order to get rid of Notorious B.I.G.. Without his hands, Giorno cannot heal anyone but Trish discovers that Giorno made a brooch into a spare hand. Unfortunately Notorious B.I.G. is still in the plane, but Trish awakens her Stand Spice Girl. Ultimately Trish manages to bring Giorno his hand and destroys the plane, plunging Notorious B.I.G. into the sea.
In Sardegna, Bucciarati's Gang investigate the Boss' past. Abbacchio uses his Moody Blues to rewind events to when the Boss met Trish's mother, but the Boss manages to kill Abbacchio. The death is too sudden, and Giorno too late to save Abbacchio. However he discovers that Abbacchio rewinded far enough in time to expose the Boss's face and fingerprints. While their attempts to investigate the police databases is fruitless, Bruno's Gang are noticed by an ally who reveals the Boss' name and power, Diavolo, and showing them the Arrow, promises them a power able to defeat King Crimson when they meet in Rome. While they depart, the Boss sees their determination and suspects that he hasn't won yet, then pursues them to Rome.
Upon arriving to the coasts of Italy, the group is attacked by another Stand which causes explosive mold growth. Moreover, another Stand user able to swim through solid concrete attacks them as well. The duo Cioccolata and Secco tries to kill Bruno's Gang on the coast but Giorno, managing to deduce how Cioccolata's power functions, enables the whole group to steal a car and try to escape from Their enemy.
However Cioccolata and Secco follow them to Rome where Cioccolata's Green Day causes chaos. Giorno and Mista manage to pin down the helicopter Cioccolata is in and leave Secco to Bruno. Near the helicopter, while Mista is taken down, Giorno manages to kill Cioccolata with the help of the last of the Sex Pistols.
Bruno also manages to kill Secco, but the group is split, enabling Vinegar Doppio to approach their contact first. Jean Pierre Polnareff, who had been working against Diavolo for many years, confronts the Boss first, and has no choice but to use the Arrow on his Silver Chariot. Chariot Requiem appears out of Silver Chariot and switches everyone's souls. Great confusion arises as Giorno finds himself in Narancia's body, and Diavolo is now inhabited by Bruno's soul. Moreover, Chariot Requiem is now ferociously guarding the Arrow and no one can approach him without their own Stands attacking them. Finally Diavolo's souls infiltrated Bucciarati's Gang and is sabotaging their attemots at retrieving the Arrow, having killed Narancia.
Diavolo reveals himself at the opportune moment and almost retrieves the Arrow, but Bruno manages to work out Chariot Requiem's weakness. Chariot Requiem is destroyed, and everyone returns to their original bodies. Giorno takes the Arrow and pierces Gold Experience with it, unlocking Gold Experience Requiem.
After Gold Experience Requiem overpowers King Crimson's time erasure and punches Diavolo into the waters, Mista and Trish express an urgent need to find Diavolo. Giorno, however, remains confident that Diavolo is finished. Giorno eventually take the lead of Passione as a group of dignified men Stand before him.
(The information below derives from a Light Novel not written by Araki. As such, it may or may not be considered canon.)
After defeating Diavolo, Giorno reveals himself as the Boss, claiming that he doesn't want traitors to endanger the boss' daughter in an attempt to find his identity. Attracting the attention of the Speedwagon Foundation, Giorno accepts to cooperate with them and as a gesture of good will, accepts to destroy a Stone Mask. At the same time, Giorno enlists Fugo to help kill Passione's narcotic team alongside operatives Sheila E and Cannolo Murolo. The three manage to fulfill all their objectives.
Giorno meets with Fugo shortly after the latter's defeat of Massimo Volpe, healing his injuries with Gold Experience. After talking to Fugo about the personal progress which he had made and his reasons for sending Fugo off to stop the narcotics team, Giorno finally gains Fugo's allegiance.
Stone Ocean (2012)
While Enrico Pucci's actions attracted three young men who were all DIO's sons to Florida, Giorno was nowhere to be seen despite having DIO's blood in him. On the page containing Rikiel's privilege card, it hints that Giorno may be in Florida after all, though the reason he wasn't drawn to the priest is unknown (were he to have made an appearance, he would have been 26 years old).