La famiglia Dadan (ダダン一家, Dadan Ikka?) è un gruppo di banditi di montagna diretto da Curly Dadan, e abitano sul monte Corbo, sull'isola Dawn, nel mare orientale. Garp afferma che il numero di reati che hanno commesso sia maggiore del numero di stelle che ci sono in cielo.
The two known members of the family other than Dadan herself are Dogra and Magra, though there are other members seen. When Dadan was blackmailed by viceammiraglio Monkey D. Garp, they were forced to take care of his adoptive grandson Portgas D. Ace and later his blood-related grandson Monkey D. Luffy. The two boys were to hunt and clean for the gang (which they rarely did), as well as sometimes steal for them, and they were joined by a noble child Sabo, who was ashamed of his family status. Eventually, all three boys left for piracy, but Sabo presumably died after being shot down by World Noble Jalmack at age 10. Ace and Luffy each departed when they reached 17, but Ace was eventually killed by Admiral Akainu during the Battle of Marineford at age 20. Luffy, currently 19, is the only known survivor of the three children, and has the Dadan Family's full support to live proudly.
Taking Care of Garp's Grandchildren
Garp first approached the Dadan Family and had them to take care of Ace, in exchange of having the Marine turn a blind eye on their crimes, as Garp himself did not have the time to do childcare. Years later, Garp brought Luffy to Dadan for the same reason. Ace and Luffy did not get along at first, nor did Luffy with the bandits. However, as time passed, they all got along well, having to know each other. Sabo also joined them initially, having run away from his home out of shame, but was eventually recaptured by father through the hiring of the pirati di Bluejam.
Dadan Family vs. Bluejam Pirates
Ace and Luffy were forced to help Bluejam to load explosives into the Grey Terminal for the sake of the Goa Kingdom to have a good reputation for the incoming World Noble Jalmack, then were left to die in the blazing inferno. However, with the Dadan family coming in to save the two boys, Dadan and Ace defeated Bluejam and managed to return to Mt. Corvo.
Departure of the Three Children
Eventually, Sabo, who once again escaped from his family, set sailed to the seas in his dream of being a pirate, but was shot down by Jalmack for cutting in front of his ship. Dogra saw this and reported, much to the horror and sorrow of everyone else. Ace then told Luffy to live strong, for Sabo's sakes, and the two trained alongside with the Dadan Family. Eventually, when each reached 17, they departed into the sea, much to the Dadan Family's tearful moments.
When Ace died in Marineford, the Dadan Family went down to Foosha Village to confront the returning Garp. Dadan herself brutally beat him up for not protecting Ace. She yelled at him for choosing duty over his own family. Then shouted her support to Luffy, who managed to escape from the war thanks to Trafalgar Law's assistance.
The Straw Hats' Return
When the Dadan Family received newspapers detailing the return of Luffy and his crew, they throw a party while Dadan is shown making a scrapbook of Luffy's actions, much like what she did with Ace's.