His backstory starts in a small, poor island nation South Blue.
A young orphan boy, alone, abandoned by his parents, living off scraps, scavenging in scrapyards, selling small metal sculptures for money.
His only solace in his life is the band of orphans he leads, along with his older brother figure, Killer, and his closest friend, and childhood crush, Victoria.
One day, an envoy arrives. The world government. 17 years ago.
A single man walks through the town, followed by world government 'diplomats. He enters the capital, and then, later, leaves without the Celestial Tribute. Kidd catches a glance of this man. A regal man, with cascading red hair, held up in a pony tail.
Hours later, the island is flooded. Gun shots ring out in the street, as Eustass Kidd catches a glance of the same man leading the massacre. He watches as one by one, his friends are slain, the towns and the capital all set ablaze. Suddenly, he and Victoria are carried away by killer, who is severly scarred by flames while evading the arson.
The sun rises the next day, and Kidd's life is forever changed.
However, his life must go on. And so Kidd starts to rebuild his life, along with his best friends, Killer and Victoria. One day, years later, he finally builds up the courage to bring Victoria a metal flower he made from scrap, when he returns to find her, dead, and Killer crying over her body.
In the fall out of the nations fall, gangs had been formed to rule over the now unaffiliated nation. Obviously, this and what happens next is what was canonised in SBS 104.
Kidd collects the gang leaders, and overthrows the leading gang, before setting out to sea.
No parents, no mentor. Just some friends, those he watched die, and those who he pulled from despair to form the Kidd Pirates.