They appear once the player's character has reached the Tavnazian Archipelago region (i.e. Lufaise Meadows after clearing Promyvion Dem, Holla, and Mea) and steal the player's Mysterious Amulet Key item while they are unconscious. The Chebukki Brothers are considered to be troublemakers by the people of the Archipelago, and Prishe has a tendency to threaten them in order to keep them in line.
After the Chebukkis leave the Tavnazian island, they try to find a place in the world. First, they embark on a search for their father, menacing the majority of the Windurstian Ministers in the process. Eventually they find their way to Jeuno, where they worm their way into the Palace's authority system, becoming "respected dignitaries". After being punished there, they decide to join Tenzen and help him, stealing a warship from the Jeunoan Armada and becoming "Sky Pirates". After ending up in Al'Taieu, they decide to masquerade as the children of the Zilart Prince, hoping to find a father figure. Eventually, the will of Promathia becomes so strong that they actually believe that Promathia is their father, doing everything they can to help him.
Following the defeat of Promathia, the children plummet to the ground, landing in the water. A ship saves them, then after hearing their annoying antics, decides to leave them on Purgonorgo Isle, where they encounter a strange Tarutaru. After bombarding him with a Meteor, the man realizes that the children are his own children, and that he is their father. The Chebukki children find their father, presumably living with him from then on.