Personality
Giorno began as an unhappy and lonely child until he befriended a gangster. As the gangster protected him, Giorno learned that he could trust people and since then, he has become a more confident person.
Giorno is an ambitious person, and readily takes any occasion to close on his final goal of being a "Gangstar". Upon beginning to cooperate with Passione gangster Bruno Bucciarati, Giorno wastes no time in infiltrating it, and steadily works Bruno's way up the ranks, his assassination of Polpo hinted to be partially a way to get a promotion for Bruno. Later Giorno also tried to personally approach the Boss of Passione, and planned to plant a bug on him.
A very serious teenager, Giorno doesn't stray off his mind from his mission, and the goals he's set for himself, although Giorno has occasionally thought about more mundane subjects, such as the delicious pizza margherita from Naples, right before being attacked by Notorious B.I.G.. Giorno tends to approach things with a calm demeanor and immense composure, but he can still be anxious when things go south. He rarely allows his anger to get the best of him, but shows moments of tranquil fury against certain enemies.
Giorno seems to have inherited both of Jonathan Joestar and Dio Brando's traits, with the former's being present towards peers and allies, and the latter's towards enemies. He has a good heart and wants to help out anybody who has shown him kindness, but casually disregards law, having been a petty thief at the start of his encounter with Koichi and bribing the airport security guards to keep doing it, overall following his own morality without compromise. Giorno values life greatly and always seek to never leave someone to die, even putting himself in danger if another can stay unharmed. In the same vein, Giorno seeks to put a stop to the drug trafficking which is ruining countless lives in Italy. On the other hand, Giorno has no trouble or qualms in punishing those that needlessly and intentionally hurt other people, as shown when he engineers Polpo's death to avenge a janitor his Stand killed, and in fact will be particularly ruthless and vicious doing so. Save Bucciarati, whom he spared because he recognized that he was a moral person, Giorno has killed everyone he fought against without remorse or hesitation, and all died a gruesome death. For instance, he had Melone bitten by a venomous snake, and has lied to Cioccolata about sparing him, merely buying time for a bullet to transform into a scarab and devour Ciocolata's brain before pummeling him into a garbage truck.
Usually introverted, Giorno regularly maintains a facade of confident boldness, backed up by his intelligence and his natural charisma, to make him look like a flawless person by his peers. This is especially visible upon his first meeting with Bruno's team, switching from a passive and polite demeanor to a self-assured persona when they try to bully him, and impressing the whole team. When alone, Giorno has shown to be a more goofy person and only in these occasion does he allow himself to think about something else than his goal or act seriously. His parents' abuse encouraged his introverted nature and his habit of observing others, resulting in his deductive skills but also making him a silent person until he has something of importance to say. On the contrary, when Giorno has an enemy at his mercy, he is prone to chitchat, either exposing his way of life or analyzing their thoughts, much like his father Dio, and even taunted Diavolo during their climatic battle. Giorno is polite in his interactions with figures of authority or his superiors, and in fact doesn't swear at all. He nonetheless doesn't shy from expressing his opinions even if they contradict those of his interlocutor, as seen when he argues against Abbanchio about abandoning Fugo to the enemy.
Giorno also has the habit of assuming alone the responsibility of his actions, leading to a temporary state of panic when his plans fail. Giorno is very upset when he cannot do anything about his situation, going as far as to deeply apologize to Mista for being unable to use his Gold Experience against Ghiaccio's White Album. During the events of Vento Aureo, he slowly learns to trust his teammates with even his imperfections and limits and instead of assuming the reins alone, fully cooperates with them.
Making Giorno repeating himself greatly annoys him, since it means his interlocutor is stupid. This is especially ironic, since his own battlecry consist of angrily repeating himself "Muda!". In addition, much like Jotaro, Giorno is annoyed by the numerous girls flirting with him and bluntly dismisses them.
Relationships
Family
- Dio Brando: While Giorno has never been shown interacting with his birth father, he has been shown to value his birth father to some degree as his wallet was revealed to contain a photograph of Dio. Giorno does inherit some of Dio's ruthless and brutal nature, as well as his ambition and charisma. However, he does not use it for evil ends. Giorno even uses the "WRYYY!" scream at one point.
- Jonathan Joestar: Unknown to even Giorno, his biological ancestry comes from Jonathan's DNA, as Dio conceived him using Jonathan's body, this allows Giorno to gain the Joestar Birthmark. From Jonathan, he also appears to have inherited his noble, polite, and overall kind nature toward good people, observed by Koichi to a degree. Even though Dio is the one whom conceived Giorno, and is believed by the boy to be his father, Jonathan is technically and by all means the father as well.
- Mother (surname Shiobana): Giorno's mother had seldom cared for him when he was a child, viewing him as a hindrance to her party life and left him in the dark, where he was too scared to even cry.
- Stepfather (surname Giovanna): Initially, Giorno's stepfather would often beat Giorno when his mother was away. This changes after Giorno meets the gangster, after which the stepfather was likely intimidated out of trying to beat Giorno again.
Friends
- Unnamed Gangster: When he was little, Giorno saved a wounded gangster by lying to his enemies about where he was. Incidentally Gold Experience subconsciously intervened by making the herbs around the gangster grow. The gangster was grateful and ensured that Giorno would never suffer in his life, making Giorno's father stop beating him, and stopping anyone from bullying him. He taught Giorno that there was good in humanity, and though the gangster objected to him joining a gang, Giorno dreamed of becoming a "gang-star".
- Bruno Bucciarati: Giorno and Bruno met as enemies, but Giorno deduces from the flaws in Bruno's tactics against him that Bruno was a good person and decided to work with him. From that point on, the two have formed a relationship of mutual trust, even with Giorno unconditionally accepting that Bruno will not help him if he is found out as an enemy of Passione. After Bruno's soul is finally put to rest, Giorno immediately fights Diavolo, revealing his emotions towards his friend's death.
- Guido Mista: Mista is one of the nicer people initially to Giorno in the gang when he first joins and is quick to grow to him seeing Giorno in action alongside them. The two frequently team up together and have a lot of faith in each other's abilities, at one point combining their Stand powers in a moment of doubt to capture a helicopter. By the end of the manga, Mista and Giorno are perhaps closer friends than the rest and continue their work together in the gang when Giorno takes over as boss.
- Narancia Ghirga: Narancia shows himself to be of higher stature to Giorno due to being older. However, Narancia later trusts Giorno to fight with him against Squalo and Tizziano. Giorno, after his sudden death, places a grave for Narancia and vows revenge against his killer.
- Pannacotta Fugo: Fugo initially saw Giorno as an arrogant punk, like Abbachio. During the struggle with La Squadra di Esecuzione member Illuso, he sees Giorno's worth as he sacrifices his hand, temporarily, to trick Illuso to be killed by Purple Haze, earning Fugo's respect.
- Leone Abbachio: Abbachio is highly suspicious toward Giorno's presence in the gang, even going as far as to deny Giorno the right to see his Stand in use while he tries to interrogate an enemy, during which time Giorno passively takes the abuse and tries to act in cooperation. During the battle with Illuso however, Abbachio tries to sacrifice himself to allow Giorno to retrieve the key to the turtle shell and get it to the rest, and later shows a begrudging respect for him when he defies this and stays to save the lives of all the members involved in the battle.
- Trish Una: The two don't interact as much, but Trish is seen to believe in Giorno's ability, and likewise Giorno sees potential in her as he leaves her with a new hand for him during the battle with Notorious B.I.G., a gambit which could have cost him the use of his Stand if she had failed to return it to him and Bucciarati.
- Jean Pierre Polnareff: Polnareff, after his body switch, becomes a guardian for the Stand Arrow and stays with Giorno and the newly led Passione with the rest. Later he goes on to put Giorno in contact with The Speedwagon Foundation to enable him to use the mob's resources for good purposes.
Enemies
- Diavolo: As the Boss of Passione, which was selling drugs in the streets, Diavolo was de facto Giorno's archenemy. However both didn't know each other until very late in Part 5. Knowing nothing about Diavolo, Giorno sought to approach him in order to take over Passione, but Bruno's open rebellion hasted his plan. While Diavolo learned very quickly how resourceful Giorno was and treaded carefully around him, he still treated him as inferior, calling him a "brat". On the other hand, Giorno only got to interact with Diavolo when he acquired Gold Experience Requiem and used the one moment to challenge and taunt him.
- Polpo: Giorno met Polpo to pass the test to enter Passione. Giorno and Polpo were civil toward each other, but Polpo only saw Giorno as a potential tool and used his position of power to grimly warn the teenager about misconducting oneself. On the other hand, Giorno began to despise Polpo as soon as Polpo's Black Sabbath killed a hapless civilian, prompting him to kill Polpo as soon as he could.
- Baby Face: Giorno and Baby Face were enemies, and the Stand Baby Face tried to assassinate Giorno to make a getaway after capturing Trish and Bruno. Baby Face grew increasingly frustrated at Giorno's determination to the point it forewent any precaution and tried to fight him openly. Ironically, Giorno thanked Baby Face for giving him enough trouble to be pushed into a wall and progress. It didn't prevent Giorno from summarily killing it and sending a venomous snake to its user, Melone.
- Cioccolata: While Cioccolata didn't think much of Giorno, only noticing that he discovered Green Day's ability rather rapidly, Giorno witnessed the ruin Cioccolata's Stand brought to Rome, and despised the psychopath. When Giorno defeated Cioccolata, he reminded the mad doctor that he didn't deserved to live and vented his scorn with a lengthy pummeling before throwing Cioccolata into a garbage truck.