A family of air pirates known as the Bonnes have gone into debt to build themselves an impressive airship, which they call the Gesellschaft. Now they're ready to go all out and earn (steal) the money necessary to pay it back.

Teisel, head of the family, and the little brother Bon scout the Nakkai Desert along with some of their little mechanical minions, the Servbots. They seek to locate the Nakkai Ruins, wherein there's said to be a legendary refractor called "Diana's Tear". However, just as the Bonnes reach their destination and prepare to enter, they are interrupted by a flying robot.

Glyde has arrived, henchman for Lex Loath, the man from whom Teisel had borrowed the money. Instant payment is demanded, or else. Teisel tries to explain that they're about to get the big pay-off, but Glyde insists that time is already up. A battle ensues, in which Glyde emerges victorious.

Back aboard the Gesellschaft, the middle child of the family, Tron Bonne, becomes worried when she loses contact with her brothers. Traveling to their last known location in the Nakkai Desert, she finds a few of her Servbots, saddened and crying. They explain that Glyde has taken the two Bonne brothers captive until they "work off" their debt.

Tron returns to the Gesellschaft and orders her 40 servbots to search the ship. They find and bring to her the IOU written out to Lex Loath for 1 Million Zenny. Tron makes up her mind to go out and continue what her brothers had started. She will pay off the debt and free her brothers herself by gathering the money any way she can.

Exploring ruins, robbing towns, pillaging ships, rustling cattle... the misadventures begin!