Gyro lived a roughly normal life until his late childhood, upon which he was trained in the arts of the Spin by his father Gregorio Zeppeli. The Zeppelis being renowned doctors as well as servants of the King of Naples, Gyro lived in certain comfort. At age thirteen, Gyro began his training as a royal executioner in secret. At the same time, he was an apprentice surgeon for the family. In his late teens, Gyro was to become the next royal executioner as well as a surgeon, following his father in both aspects.One day, one woman scheduled for execution became violent and almost killed an executioner. During the struggle, Gyro lost his collar hanger. When he found it again, it was in the hands of a little boy named Marco who was found guilty of treason because he served a traitorous lord. Disturbed by the false charges as well as the fact that Marco was his first execution, Gyro asked for Marco's appeal. Unfortunately, his efforts were vain, but a lord of Naples explained to him that the king would give amnesty to political criminals if the country suddenly gained prestige, such as winning a famous horse race. Thus, against his father's wishes, Gyro subscribed to the Steel Ball Run race.
Gyro departed from Genoa, Italy earlier in May and arrived in the US on May 22.
Shortly after joining the Steel Ball Run race and before it begins, Gyro goes into town where he duels a man using his 'Spin' and steel balls as weapons. When the paraplegic Johnny Joestar touches one of Gyro's spinning orbs, it causes his paralyzed legs to move for a moment. Gyro attempts to convince Johnny that it was simply a reflex of his legs but fails, as Johnny is not convinced and joins the Steel Ball Run race to follow him in order to learn about the Spin and how to move his legs once again. Still, Gyro takes an interest in Johnny's actions, specifically his choice of horse, and gives him a hint to use the 'Spin' to mount his horse.
At the start of the race, Gyro rushes ahead of every participant, taking out Urmd Avdol as well as Diego Brando, two of the Steel Ball Run's favorites, to everyone's shock. Still leading the race, then takes a dangerous shortcut through a forest during which he discovers his most serious challenger during this stage, Pocoloco. Thanks to his luck, Pocoloco eventually overtakes Gyro by sliding down a slope on a cow's skin Gyro unsuccessfully tries to stop Pocoloco by throwing a Steel Ball which endangers Sandman, who was running down a cliff. Nonetheless, Gyro crosses the finish line first after a lengthy dash, helped by the tailwind.
However, Steven Steel voids Gyro's performance for endangering the competitor Sandman and relegates him to 21st place, which outrages him. However, impressed by Johnny's determination, Gyro invites him to race with him on the second stage, determined to get first.
The racers line up, preparing to race across 2000 km of Arizona Desert for the second Stage. Against Johnny's advice, Gyro decides to take another shortcut through 120 km of desert and Johnny follows Gyro, both pursued by the fellow racer Mrs. Robinson. Mrs. Robinson soon attacks the duo, but Gyro quickly defeats him with the Spin.
Camping for the night 50 km from the second water point, Gyro and Johnny are approached by Andre Boom Boom, Benjamin Boom Boom and L. A. Boom Boom who can forcibly magnetize someone when the victim touches Andre's blood. Unable to fight people who can control metal, Gyro and Johnny flee from the Boom Booms, but both are now magnetized. Gyro and Johnny eventually meet Mountain Tim, who was tricked into thinking Johnny murdered participants to the race. Because the three of them are under the influence of Tomb of the Boom, they attract each other and eventually are stuck together in iron sand, at the mercy of Benjamin and L.A. Boom Boom. However Johnny develops a Stand of his own, and manages to kill Benjamin as well as cripple L.A., who curses Gyro and assures him that other mercenaries will come after him.
At a checkpoint, Gyro and Johnny then have to fight a past terrorist from Naples, Oyecomova. However, Gyro and Johnny manage to work together to kill him. After attacks from other participants such as Fritz von Stroheim as well as other Stand users like Pork Pie Hat Kid, Gyro discovers that Johnny is carrying a corpse part which is likely why everyone is attacking them.
Gyro, distracted at the last moment by a newspaper, finishes the stage at the fourth place.
Although Johnny is interested in the Corpse Parts, Gyro's mind is still focused on winning the race. In a small village in the Rocky Mountains, Gyro and Johnny search for the Eyes, but also battle Dr. Ferdinand's army of dinosaurs. Dr. Ferdinand reveals that the Corpse Parts are highly sought after. At the same time, Diego, who acquired the Stand Scary Monsters takes away the left eye while Gyro has the right eye.
However, at the final run to the end line of the third stage, Gyro is beaten by Diego when the jockey sneakily spits a small rock toward Valkyrie, slightly injuring the horse. Gyro finishes at the fourth place and concludes that his loss is due to his own lack of drive in the race.
Gyro and Johnny then race peacefully during 600 km of the 1250 km of the fourth stage.
At about 650 km from Kansas City, Gyro and Johnny formally meet Hot Pants, a fellow racer. Although Gyro doesn't like nor trusts Hot Pants who attacked them earlier, they are forced to ally themselves with him as gunslinger Ringo Roadagain blocks their way out of a forest. A shootout ensues, Johnny and Hot Pants are injured while Gyro is spared out of spite by Ringo. It is at this moment that Gyro acquires a genuine and selfish motivation to win, and challenges Ringo, this time winning against him. Gyro then heals Hot Pants and Johnny, but steals the latter's sandwiches to annoy him.
As they approach Kansas City, Gyro and Johnny challenge Diego again in a race during a heavy rain. Gyro manages to win against Diego, whose horse is injured, putting the Englishman out of the race for a certain amount of time. Later they meet Lucy Steel, who learned about the Corpse Parts and unwittingly antagonized he American Government. Asking for help, Lucy gives them the Spine as token of good faith, and Gyro defeats Blackmore, an agent who trailed Lucy. Gyro however suggests that Lucy goes back to steal Valentine's Heart. The Spine also gives them the location of the three next Corpse Parts.
During the fifth stage, Gyro and Johnny race peacefully for about 300 km.
However they are attacked by Diego and Sandman, the latter's ability to give life to sounds being problematic since it destroys Gyro's Steel Balls. Cornered into a river, Gyro manages to teach Johnny to take inspiration from the surrounding nature in order to create an infinite rotation. Johnny's Tusk ACT 2 kills Sandman while Diego is already far away. Weakened by the fight, they cannot stop Hot Pants from stealing their Corpse Parts.
They then finish the fifth stage peacefully.
At the beginning of the sixth stage, Gyro and Johnny meet Sugar Mountain, a young girl living in a tree who guards the Ears and the Right Arm. Gyro manages to acquire both plus a hefty amount of precious goods. Their joy is cut short when they learn that they have to trade the goods by sunset, or they'll be absorbed into the tree.
In a nearby city, Gyro has difficulties spending everything in time, plus Eleven Men are stalking them, looking to kill them. Gyro decides to go into a clandestine casino to gamble, but he and Johnny are interrupted by the Eleven Men. A shootout ensues, during which the enemy proves too much, but Gyro convinces the gangsters working in the casino to protect him in exchange for the goods. As sun sets, Gyro transforms himself into a tree, having not thought of trading the Corpse Parts, and Johnny is forced to trade them to the last of the Eleven Men.
Near the Michigan Lake, Gyro and Johnny confront another duo of government agents. Wekapipo and Magent Magent. While Magent Magent is disposed of rather quickly, Wekapipo's expertise in the art of the Spin proves dangerous as Wekapipo made sure to seal off Gyro's ability to draw from nature, and Gyro almost dies. However due to a coincidence, Gyro is able to look a snowflakes to overpower Wekapipo. Instead of letting him die, Gyro asks Wekapipo to go look for Lucy Steel.
Having victory on their side, Gyro and Johnny immediately obtain the Legs from a wolf and easily finish the sixth stage at the first and second place.
Gyro and Johnny ride peacefully for 12 days, until one night, they see Hot Pants riding away. Gyro and Johnny follow her into a local garbage dump, but they realize it was a trap from the Stand user Axl RO, whose Civil War immobilizes Gyro. However Johnny saves them both due to his Stand evolving another time.
Unfortunately, Valentine intervenes at the last moment and steals away all the Corpse Parts of the competitors save Diego's Eye. Their luck runs out, and Gyro finishes the stage at a disappointing 6th place.
In Philadelphia, Gyro and Johnny decide to follow Diego and acquire his Eye. However, Valentine, using Dirty Deeds Done Dirt Cheap's power to his advantage. Gyro loses time fighting his last agent D-I-S-C-O then investigate a shootout during which Johnny disappeared. At the same time, Valentine takes the Right Eye from Diego and Diego kills Wekapipo to escape the parallel dimension in which he's been imprisoned.
Johnny manage to work out the power of Valentine's Stand, and a reluctant Gyro accepts to help him pursue Valentine, revealing that even against Valentine, there is another level of Spin which could overpower him. Gyro and Johnny follow Diego and Hot Pants, observing from afar their clash between the three. It is not until Diego dies that Gyro and Johnny approach the train. However, they didn't plan for Lucy, now transformed into the Corpse, to cause a space distortion making the landscape converge toward her. As Gyro tries to escape this strange phenomenon, a carp bites into his finger. Later when Gyro investigates the locomotive, this one bite has moved to his carotid, severely injuring him.
Now, Valentine has unlocked Love Train, a pocket dimension against which harm rebounces, making the President invulnerable. However, Gyro manages to forcefully tear off some of Valentine's hair. Gyro and Johnny take a respite, then charge toward the President, gambling on the potential of the Spin.
Nonetheless, Valentine manages to injure Johnny in the subsequent clash, forcing Gyro to throw one Steel Ball in a hurry. Johnny is only saved by Steven Steel who gives Lucy to Gyro and begs him to take her away from Valentine. Gyro manages to save Lucy on his horse and dashes toward the ocean, setting the stage for a duel against Valentine.
In the final battle against Valentine, Gyro uses the most advanced technique of the Golden Rectangle: the "Super (or Cavalry) Spin", which is created by invoking the golden rectangle while riding a horse to gain momentum. By combining this technique with his newly developed stand Ball Breaker, his attack becomes very powerful. Although his technique is very effective, it is not enough to beat Valentine, who resists his injuries long enough for Gyro to die from his own wounds. However, before dying, Gyro gives his last lesson to Johnny, allowing Tusk to reach ACT 4 and giving Johnny the power to defeat Valentine.
Gyro then reappears as a spirit, saying goodbye to his friend and ascends to Heaven.