Venturing into Endra, a hidden realm beneath Earth's surface, young Shun Asanaga, a cheerful 15-year-old from the 'Land Above,' stumbles upon this mystical land after a chance encounter with a crystal tied to his father's work. Here, amidst the grandeur of the shining Adamas and vibrant skies, he crosses paths with Prince Emirio, a vengeful heir to the throne at just 16 years old. As Emirio's desire for retribution clashes with the might of King Deruzain, Shun finds himself embroiled in their conflict. Bound by fate and divided by their origins, the two youths navigate a world where destinies collide and choices shape the future they seek.