The Simon Famiglia is a Mafia Famiglia which has had ties with the Vongola Famiglia ever since the founding of their Famiglias; their respective bosses being best friends. However, over time, they've become an extremely small and weak Famiglia, so much so that Reborn, who has an extensive knowledge of the Mafia world, didn't know about them.
The Simon Famiglia does not use the standard Dying Will Flames. They are the first and only known Famiglia to use the Dying Will Flames of the Earth, a power said to be able to rival the Dying Will Flames of the Sky.
The founders of the Simon Famiglia and the Vongola Famiglia, Simon Cozzato and Giotto, were excellent friends who would never fight each other. During the massive mafia war against a rival mafia family of Vongola, Demon Spade led Cozzato and his family into a trap where they were cornered by the enemies. Fortunately, Giotto saw through his Mist Guardian's plan and ordered his remaining guardians to save the Simon. To prevent themselves from being a burden to the Vongola, the Simon family members went into hiding and faked their deaths in order to deceive Demon Spade's eyes. This decision led both families to make an oath with the Vindice that if the two families were to fight against one another, the Vindice would deliver the punishment. The Simon Famiglia isolated themselves in their island from the outside world and never met the Vongola for years.
Due to Demon Spade's plotting, the tenth generation Simon Famiglia was led to believe that Giotto had betrayed Simon Cozzato, leaving them and their Famiglia to die. The grudge from this incident was still evident, as the current Simon Famiglia wanted revenge on the Vongola for what had transpired.
However, after defeating Demon Spade, the Simon and Vongola reconciled, becoming allies once again.
- Simon Rings - rings held by the current generation's boss and guardians. Each ring is powered by Dying Will Flames of the Earth.
- All the members of the Simon Famiglia have red eyes.