Gelaro is a direct descendant of Bertesca Primo and the only heir to the Famiglia. Due to Bertesca Famiglia's isolation, he and his Famiglia are persecuted by other mafia Famiglias as their Famiglia was weak and small. He spent almost his entire life at Catafalco Island with his parents and grandfather, who took care of him and taught him about their Family's duty, which is protecting Parvento's seal.
Several years before the main storyline of the game, during one of the persecutions, however, Gelaro's father was killed, leaving him distraught and orphaned, with Banchiza and his remaining Famiglia members taking care of him in his parents's place. One day, during a stroll around the Bertesca mansion, he found the frozen Parvento and was shocked when the latter talked to him despite being in his frozen state.
Recognizing Gelaro as the current Bertesca Boss, Parvento lied to him that their Family's duty is actually protecting him from Vongola, who only used their Famiglia as a stepping stone and just left them to suffer, and that the only way to regain their honor was to destroy the Vongola with his help, deceiving him to free him. Gelaro, not knowing the full truth of the past and wishing for freedom, believed Parvento's words and convinced his remaining Famiglia members to seek revenge on Vongola and to free Parvento from his seal.
Before the Choice Battle, while Tsuna is training with Basil and Reborn, Gelaro appears before them, introducing himself as Vongola Snow Guardian and the tenth Boss of Bertesca Famiglia. At first, Tsuna, Reborn, and Basil don't believe him until he shows them his Snow Vongola Ring and Snow Flame. He then freezes the Vongola Rings with his power and told Tsuna before he left to come to Catafalco Island if he wished the Vongola Rings to be unfrozen.
Chapter 1-6 Edit
After Tsuna, Reborn, and Basil defeated Grandi and destroyed the Sky Crystal at the Sky Temple, Gelaro is seen in front of spikes of ice as the orange colored spike shattered, commenting that it has began. At this time it's revealed that his reason for freezing the Vongola Rings seems to be for Tsuna and his Guardians to unfreeze their Vongola Ring, and, in the process, deactivate the 7 Crystals scattered throughout his island. Every stone that is deactivated will break the ice spike of the same flame type that seals a mysterious being sealed within them. For most part of the game, he stayed within the frozen room and commented each time the crystal started to break.
Chapter 7 Edit
He once again confronted Tsuna and his Guardians, shortly after Chrome destroyed the last crystal that sealed the mysterious being, which later Banchiza revealed to be Parvento. He briefly spoke to Tsuna and his Guardians about his true plan, but retreated to make sure that Parvento is freed. At Bertesca mansion, he confronted Tsuna and his Guardians again who intended to prevent Parvento's revival. He was defeated, but able to buy enough time until Parvento completely freed from his seal. At this time, it was revealed that his real flame is Sky Flame, while the Snow Flame and the Vongola Snow Rings were just clever camouflages. He then revealed his and his Famgilia's past and his reason for challenging Vongola. After hearing this, Tsuna tried to explained the true duty of his Family, but Gelaro refused to believe this and went to Parvento's place while Tsuna and his Guardians returned to the Vongola Ship to arrange plans.
At the underground room where Parvento was frozen, Gelaro demanded Parvento to wipe out Vongola, only to be attacked by him. Parvento then revealed the entire truth, and that he has been lying to him and his Famiglia all this time. Gelaro fought against him, but immediately defeated.
Later, Tsuna and his Guardians found him lying unconscious and injured on the corridor to Parvento's room. As ordered by Tsuna, Ryohei healed him with his Sun Flames. Immediately recovered, Gelaro apologized to Tsuna for not believing him and wishes to defeat Parvento together.
After defeating Parvento, Parvento intended to kill all people in entire island by exploding himself, but Gelaro and Tsuna were able to prevent this by using Zero Point Breakthrough: First Edition together, freezing the explosion. Afterwards, Gelaro's Vongola Snow Ring shattered as it already reached its limit. Once again, Gelaro properly apologized to Vongola Famiglia, to which Tsuna immediately accepted.
Seeing that Gelaro still felt guilty and down, Tsuna invited him and his Famiglia to their party at their Vongola Ship to celebrate their victory. Expressing his gratitude, Gelaro swore that from then on the Bertesca Famiglia would always support the Vongola, thus becoming their ally once again. Tsuna then asked what would they do next, since Parvento had been defeated. Gelaro finally decided that he and his Famiglia would still stay at the island to protect the villagers, but promised that they wouldn't live in isolation like they used to be and that they would visit the Vongola again.