It may contain SPOILERS.
Continue reading at your own risk.
The Cervello is a mysterious, all-female organization that serves as judges in Mafia battles. Byakuran has stated that the Cervello's 'speciality' is to judge fairly, and that they are never biased, even if they support one team over another. They currently serve the Vongola Famiglia, but will work for the Millefiore Famiglia in the future.
The Cervello are masked women that act as judges in games or tournaments. Supposedly, the Cervello are loyal only to the Vongola Famiglia, but they work for the Millefiore Famiglia in the future.
Their roles include:
- Keeping the rules in place.
- Informing contestants of the rules.
- Serving someone with a higher position.
They always appear in pairs with matching outfits. Each Cervello's clothes vary, but resemble the current Japanese trends. When they approached Byakuran to offer him the Sky Mare Ring, they were seen wearing grey hooded robes. Every Cervello has exactly the same mask on their eyes and long pink-lavender hair, although in different positions the hair lengths vary.
All of the Cervello members seen in the series display the same calm and matter-of-fact personality. Xanxus seems to think they are cunning.
They appear to consist of only women, although it is unknown whether this is true as they appeared to have men of other appearances fixing the school with illusions; however, it is not determined whether these men are disguised pink-haired Cervello.
The Cervello appeared right after Iemitsu Sawada says they're to await further instructions from Vongola Nono. They explain about how they will judge the Vongola Ring Conflict and how the matches will be held at Namimori. They then disappear until the night of the Sun Ring Battle.
During the Lightning Ring Battle, they oversaw the battle until the very end, unblinkingly watching as Lambo was about to be murdered by Leviathan, and make no move. After Tsuna saves him, they disqualify both Lambo and Tsuna from the tournament and give both rings to the Varia side. Xanxus then attacked a Cervello because she attempted to stop him. The attacked Cervello was replaced during the Storm Ring Battle, looking identical to the old one.
They continue to oversee the remaining battles, until they disqualified the Varia after its true intentions were revealed. The Cervello attempted to allow the rest of Tsuna's allies help, however, the Varia had sabotaged the infrared boundary and would not deactivate. Surprisingly, all 50 members of the Varia's reinforcement squad were defeated by Lancia. With this, the Sky Ring Battle concluded and Tsuna's team was declared the winner.
Interestingly, when Xanxus is lying on the ground, and the Cervello approach him, he says that the fight had gone the way they wanted and asks if they are happy now. They reply that they were always neutral, but that everything had been decided beforehand. As Xanxus passes out, he remarks that they are "cunning foxes".
In the Future Arc, they served Shoichi Irie, obeying his orders, suggesting ideas, and accompanying him.
In the game of Choice, they acted as judges to prevent cheating and biased judging. It is also revealed that they are now a part of the Millefiore Famiglia. In the first round, they just addressed both teams as most of the rules and explanation had already been explained by Byakuran. The Cervello judges during this Choice Arc appeared to be using Sun Flames Boots to fly and watch the ensuing battle.
In a flashback, the Cervello are shown giving Byakuran his Sky Mare Ring, stating that there was no one more deserving of the Ring than him, despite Byakuran's warning of possible meddling in world domination and destruction.
- Cervello means "brain" in Italian.