|“||This is resolve! It is to carve out your destined path through the darkened wastes!||”|
—Giorno, encouraged by Mista's determination
Giorno's childhood was filled with unhappiness and loneliness due to bullies and the abuse of his stepfather. During his early childhood, he was initially cold and uncaring towards anyone, and believed himself to be scum just for the way people treated him. Those that knew him easily thought he'd grow up to become a twisted individual. This changed when he befriended an injured gangster he saved. As the man protected Giorno from those that did him wrong in return for his aid, he learned that he could trust people. Since then, he has become a more confident and solicitous person.
A defining characteristic of Giorno, and shared among his peers through him, is his resolve (覚悟 kakugo); something that can be described as his ability to make important decisions without hesitation and seeing them through to the very end, even in the face of pain, sorrow, and tragedy. An ambitious individual, he readily takes any occasion to achieve his final goal of becoming a "Gang-Star". Upon beginning to cooperate with Passione gangster Bruno Bucciarati, Giorno wastes no time in infiltrating the gang, and steadily works his way up the ranks. His assassination of Polpo was partially a way to get a promotion from Bucciarati. Later, Giorno also tried to personally approach the Boss of Passione, and planned to plant a tracking device on him.
Being a very serious teenager, Giorno's mind doesn't stray off the path from his mission and the goals he's set for himself. However, Giorno has occasionally thought about more mundane subjects such as the delicious margherita pizza from Naples, right before being attacked by Notorious B.I.G.. Giorno tends to approach many things with a calm demeanor, and demonstrates immense composure even when confronted by dangers he might not understand completely, with Koichi describing him as having a 'shining serenity' in place of where most apprehension should be. However, he can still become anxious when things go south. Giorno rarely allows his anger to get the best of him, but shows moments of tranquil, if not oppressive fury against certain enemies. At his worst, Giorno becomes desperate for solutions to problems, and can be seen yelling and breaking out in sweat when emotionally distressed, though he never reaches a level of panic to become reckless or impetuous.
With others, Giorno treats people with the amount of respect he believes they deserve based on his observations of their beliefs and actions. He 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 demonstrated kindness to him or others, but casually disregards law. He was a petty thief when he first encountered Koichi and bribed the airport security guards before stealing Koichi's luggage. Overall, he follows his own morality without compromise. Giorno believes that people are free to die how they want. However, he also values life greatly and always seeks to never leave someone to die if he himself is able to help it, even putting himself in danger if another can stay unharmed. He believes that a "will of self-sacrifice", or giving one's own life for the sake of others, is not a part of what he believes resolve is, revealed during his and Mista's battle with Ghiaccio. In many cases, he will put his own life at risk and make himself the target of injury if those actions are able to assist his allies. In reality, he carefully plans out those course of actions to ensure that he will always come out of those situations alive. Within the same vein, Giorno's dreams are rooted in his desire to put a stop to the drug trafficking ruining countless innocent 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 an innocent janitor that Black Sabbath killed, and in fact he will be particularly vicious when doing so. Except for Bucciarati, whom he spared because he recognized that the former was a righteous person, Giorno has killed everyone he's fought against without hesitation, and all have died gruesome deaths. For instance, he had Melone bitten by a venomous snake made of his own Stand and rapidly kicked Ghiaccio until his neck, stuck on a splintered lamppost, was completely impaled. In the presence of those same enemies, he is not even above lying, having deceived Cioccolata into believing that he would be spared, when in reality he was merely lowering Cioccolata's guard and buying time for a bullet lodged in his head to transform into a scarab which would devour the scientist's brain before Gold Experience finished him off; Giorno remained completely unfazed through the display.
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 Bucciarati's team. He switches from a passive and polite demeanor to a self-assured persona when they try to bully him, and impresses the whole team. When alone, Giorno is shown to be more humorous and only in these moments 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 something of importance needs to be said. On the contrary, when Giorno has an enemy at his mercy, he is prone to chitchat and speaking at length, either exposing his way of life or analyzing their thoughts in order to make them see their errors as well as the futility of their situation. Thus, he is much like his father DIO, and even spitefully taunted Diavolo during their climactic battle. Giorno is polite in his interactions with figures of authority or his superiors, and in fact doesn't swear at all, possessing consistently well-mannered speech patterns for the entirety of his journey. He nonetheless doesn't shy from expressing his opinions even if they contradict those of his interlocutor, as seen when he argues against Abbacchio about abandoning Fugo to the enemy for the sake of their objective.
Giorno also has the habit of assuming the responsibility of his actions alone, 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 effectively against Ghiaccio's White Album. Over the course of Vento Aureo, however, he slowly learns to trust his teammates and make use of their individual abilities. Likewise, the rest of Bucciarati's gang are one-by-one charmed by Giorno's resolve and courage in them, with some like Mista and Narancia even thinking him a better leader figure than Bucciarati himself. Instead of assuming control or acting by his lonesome, Giorno eventually fully cooperates with them, creating an effective, synergistic teamwork dynamic among the whole group. Even when Giorno cannot take action by himself, he often takes steps to guide his more capable teammates into advantageous situations.
Making Giorno repeat himself greatly annoys him, as he believes it means his conversational partner is stupid. This is especially ironic, since his own battlecry consists of angrily repeating "Muda!". In addition, much like Jotaro, Giorno is annoyed by the numerous girls flirting with him and bluntly dismisses them.
- Dio Brando/DIO: 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, Giorno 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, Koichi noted that the Joestar bloodline's influence is visible.
- Mother (surname Shiobana): Giorno's mother had rarely cared for him when he was a child, viewing him as a hindrance to her party life and often left him in the dark whenever she went out, where he was too scared to even cry.
- Stepfather (surname Giovanna): Initially, Giorno's stepfather would often beat Giorno when his mother was away, angered at his habit of always trying to read people (although it was his abuse that inspired this behavior). This changes after Giorno meets the gangster, after which the stepfather was likely intimidated out of trying to beat Giorno again.
- Donatello, Rikiel, and Ungalo: The three are Giorno's half-brothers. It is unknown if he was aware of their existence.
- Jotaro Kujo: While they have never formally met Jotaro investigated Giorno due to his connections to both DIO and the Joestar family. Having found out Giorno's relation with DIO, Jotaro avoided meeting him in person and trusted Koichi to judge him in his stead.
|“||This Giorno Giovanna... it looks like he has a talent for getting people to accept him.||”|
—Bucciarati, Chapter 456
- Giorno's Hero: When he was little, Giorno saved a wounded gangster by lying to his pursuers about where he was. Incidentally, Gold Experience subconsciously intervened by making the grass and other flora around the gangster grow. The man was grateful and ensured that Giorno would never suffer in his life, making Giorno's stepfather stop beating him, and stopping anyone from bullying him. He taught Giorno that there was good in humanity, and although he objected to Giorno joining a gang, Giorno dreamed of becoming a "gang-star".
- Bruno Bucciarati: Giorno and Bucciarati met as enemies, but Giorno was able to deduce from the flaws in Bucciarati's tactics against him that Bucciarati was a good person, and decided to work with him in the conclusion of their fight. From that point on, the two have formed a relationship of mutual trust, even with Giorno unconditionally accepting that Bucciarati will not help him if he is found out as an enemy of Passione, while Bucciarati assists him in rising in the ranks. Giorno is able to save Bucciarati from complete and utter defeat at the hands of the Boss using one of his ladybug brooches, causing him to mentally note how Giorno always fills him with courage. After Bucciarati'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 initially nicer people to Giorno in the gang when he first joins and is quick to grow to him after seeing him in action. Mista is the second to realize Giorno's ability to guide others without their knowledge, viewing him as a source of hope. 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 story, Mista and Giorno are the surviving members of the original six-member team, and perhaps closer friends than the rest, continuing to work together in the gang when Giorno takes over as boss with Mista as his subordinate.
- Narancia Ghirga: Initially, Narancia only interacts with Giorno by jokingly reminding him that he is his superior due to age. However, Narancia later begins to trusts Giorno who repeatedly impresses him with his supportive attitude and quick thinking. Against Squalo and Tiziano, Narancia is happy to have Giorno assist him and even believing that the gang stands a chance against the Boss if they have him. Giorno, after Narancia's sudden death, places a grave for him and mourns, promising to take his body back home.
- Pannacotta Fugo: Fugo initially doesn't have time to think much of Giorno. During the struggle with La Squadra di Esecuzione member Illuso, he sees Giorno temporarily sacrifices his hand to trick Illuso into being killed by Purple Haze, earning Fugo's respect, and making him the first next to Bucciarati to see Giorno's valor and wits.
- Leone Abbacchio: Abbacchio is highly suspicious toward Giorno's presence in the gang and constantly belittles him, notably refusing to reveal his Moody Blues to him even if the group is in danger; nonetheless, Giorno's actions still impress him. For his part, Giorno passively takes the abuse and tries to act in cooperation. During the battle with Illuso however, Abbacchio tries to sacrifice himself to allow Giorno to retrieve Mr.President's Key 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. Never shown warming up to Giorno completely as the rest of the team has, Abbacchio nonetheless loses all suspicion toward him at the time of his death.
- Koichi Hirose: Koichi was sent by Jotaro to investigate Giorno. Despite the fact Giorno cunningly stole his luggage, Koichi becomes an ally to Giorno after he sees his inner virtue, comparing it to that of the Joestar bloodine.
- Trish Una: When Giorno is first introduced to Trish, he saw her escort mission as a prime opportunity to get closer to Passione's Boss than he had originally imagined. The two don't interact as much, but Trish is seen to believe in Giorno. As Vento Aureo progresses, Giorno demonstrates a degree of care for Trish, willing to sacrifice his chance to confront the Boss in order to tend to her and ensure her well-being. During the battle with Notorious B.I.G., Spice Girl openly admits that Giorno's actions have allowed her spirit to mature. Trish, like the rest of Bucciarati's team, has put her faith and trust in Giorno by the end, awed at Giorno's victory over her father.
- Jean Pierre Polnareff: Polnareff and Giorno become allies during the fight against Diavolo, and Giorno is the most willing to listen to his advice. After his body switch, Polnareff becomes a guardian for the Stand Arrow and stays with Giorno and the newly-led Passione.
- Sheila E: After Giorno became the boss of Passione, Sheila was placed as his bodyguard. When Sheila learned Giorno killed Illuso, she was content with the way he died.
|“||About that theory of happiness you spewed... even as I look at you now, I feel no happiness at all... because victory was mine from the very beginning.||”|
—Giorno to Cioccolata, Chapter 562
- Diavolo: As the Boss of Passione, which was selling drugs in the streets, Diavolo was de facto Giorno's archenemy and target. However, both didn't know or even personally meet each other until very late in Part 5. Knowing nothing about Diavolo, Giorno sought to climb the ranks and approach him in order to take over Passione, with his daughter's escort mission being a chance that Giorno would readily take to get close to him. However, Bucciarati's open rebellion hasted his plan and allowed him to take more initiative against Diavolo and Passione as a whole. While Diavolo learned very quickly how resourceful Giorno was and treaded carefully around him, he still treated him as inferior, calling him a "brat" and "hindrance", even when he viewed Giorno as his greatest threat during the final battle. On the other hand, Giorno only got to interact with Diavolo when he acquired Gold Experience Requiem and used the one moment to taunt the boss, especially challenging his philosophy rooted in 'results'.
- 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 despised him as soon as his Black Sabbath killed a helpless 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 Bucciarati. 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 after its user, Melone.
- Cioccolata: While Cioccolata didn't think much of Giorno, only noticing that he discovered Green Day's ability rather quickly, Giorno witnessed the ruin Cioccolata's Stand brought to Rome, and greatly execrated the psychopath. When Giorno defeated Cioccolata, he reminded the mad doctor that those like him didn't deserve to live and vented his scorn with a lengthy and mortal pummeling before throwing Cioccolata's mutilated body into a garbage truck.
(The information below derives from a Video Game not written by Araki. As such, it may not be considered canon.)
- Yukako Yamagishi - Giorno has a tendency to swindle other characters in his Eyes of Heaven interactions, acting much like he did in the early chapters of Vento Aureo. Giorno, underestimating her, attempts to scam Yukako by offering a taxi ride for 8,000 yen, but she doesn't fall for Giorno's trick and demands for him to lower the price. Realizing his mistake, Giorno comments that it "looks like I decided to talk to the wrong girl." In another interaction, Yukako warns Giorno that she has come to retrieve Koichi's stolen bag (referencing Giorno stealing Koichi's luggage at the start of Vento Aureo). After the match is over, he acknowledges her ability, saying that "Koichi really found himself an unforgettable girlfriend…"
- Josuke Higashikata - Giorno steals Josuke's wallet, causing Josuke to tremble with anger upon discovering it's been stolen. Giorno notices that it "only has 12 yen," a reference to the "Shigechi's Harvest" arc. After a match between the two, Giorno notes that his Stand ability and Josuke's are similar. When paired together, the two consider themselves a great tag team and note it is like they can read each others moves.
- Jolyne Cujoh - Much like Josuke, Giorno steals her wallet, causing her to become angry, but soon realizes that there are only five dollars left in her wallet, "not even enough to buy a pizza." However, in another interaction, Giorno asks Jolyne to partner up for a fight. In their dialogue after the match is over, they reference their fathers' "catchphrases" ('Yare yare daze and 'muda'). The two feel like they had already met, likely referencing the battle between their fathers.
- Joseph Joestar - Giorno describes Joseph's ripple ability as "a feeling of numbness different from the stand".
- Old Joseph Joestar - Giorno thought Joseph was just an old man and that he was a little repulsive. Giorno also tried to scam him.
- Jonathan Joestar - When the two are the same team, Giorno will ask Jonathan everything he knows about DIO. If victorious, Giorno will mention that DIO is his father, surprising Jonathan.