Descended from the famous Galileo, three sisters – Hozuki, Kazuki, and Hazuki – possess distinct personalities and interests that never align. Their lives take a dramatic turn when a mysterious group targets them for the legendary 'Galileo Tesoro.' Oblivious to the danger, the sisters flee on their self-made airship post-attack. However, their deep-seated conflicts hinder their ability to unite in adversity. As they grapple with the secrets of the Tesoro and the enigmatic organization's motives, the bond among the siblings is tested. Brace yourself for a thrilling blend of adorable protagonists, pulse-pounding action, and tantalizing mysteries!