Zona Family

The Zona Family is a family of traveling quiz researchers. They created and manage the Grand Line Quiz ("偉大なる航路" クイズ), and are very wealthy.

Past
Some time in the past, Zona became a interested in quizzes and trivia and spent all her time reading about them. However, she died of an illness, causing the remaining family members to begin spreading her love of quizzes in her memory. To this end, they all assumed the identity of Zona, sharing information between each other to emulate being the same person.

One Piece Odyssey
Zona Lil was approached by the Straw Hat Pirates in the Sandy Oasis in Arabasta, where she asked them the Grand Line Quiz questions. Some time later, the pirates ran into Zona Annie Sue, who pretended to be Lil and asked them more questions, though the Straw Hats were confused by her seemingly rapid aging.

After the Summit War of Marineford, Zona Mam was approached by the Straw Hats, who again mistook her for the same Zona as before. She continued playing into this, confusing them even further; however, they still answered her quiz, and she left the island after coming to the conclusion that the residents weren't ready for quizzes after the war.

After Donquixote Doflamingo's defeat, Zona Dart ran into the Straw Hats on Dressrosa, and they passed the first two difficulties in his quiz. However, as he was preparing to begin the third difficulty, he was interrupted by Annie Sue and Mam, who informed the group that Lil had been kidnapped. The three Zonas rushed off to find her, and the Straw Hats did the same.

Shortly after, the Straw Hats found and rescued Lil, with the three Zonas catching up soon. They thanked them for saving her and explained the reason they acted like one person.