Curly Dadan is a friend of Monkey D. Garp and the foster mother of Portgas D. Ace and Monkey D. Luffy. Garp entrusted her to take care of Ace shortly after the boy's birth. Later, Garp also left Luffy in Dadan's care. She took care of Sabo too when he moved in.

Dadan lives on Mt. Colubo near Foosha Village. She is the mountain bandit boss of the Dadan Family and a wanted criminal.