The film centers on Asuna, a young girl who spends her solitary days listening to the mysterious music emanating from the crystal radio she received from her late father as a memento. One day while walking home she is attacked by a fearsome monster and saved mysterious boy named Shun. However, Shun disappears and Asuna embarks on a journey of adventure to the land of Agartha with her teacher Mr. Morisaki to meet a Shun again. Through her journey she comes to know the cruelty and beauty of the world, as well as loss.
Yuya Sakaki's dream is to follow in his father's footsteps and become the greatest "duel-tainer" in history - and he just might pull it off when he suddenly discovers Pendulum Summoning, a never-before-seen technique that lets him summon many monsters at once!
In 13-year-old Aoba Tsuzaki's world, everything seems normal. An over-the-top modeling fanatic, she spends her days locked in her room, happily building plastic robots. But rumbling beneath the surface, an evil enemy of mankind (the Ancient Jinki) threatens to destroy the Earth.
