Akiyuki was living a peaceful life along with his friends and family on Sentan Island. This peace was disrupted when sudden war broke out and a strange force took control of his body.

Transformed into Xam'd, Akiyuki confronts the enemy invasion in order to protect his friend Haru. Afterwards he is retrieved by the mysterious Nakiami and taken to the postal airship Zanbani, where she lives.

Nakiami performs a special treatment to contain the power of Xam'd in Akiyuki's right arm. At the same time his family and friends look for his whereabouts.

While becoming accustomed to his new environment, Akiyuki begins the distinctive training in order to control his powers.

Nakiami meets some old acquaintances of hers, and the rest of the crew wonders if she will leave the ship to join them. Meanwhile, a classmate of Haru and Furuichi who lost her entire family surrenders herself to despair.

Kujireka asks for Nakiami's support, but is utterly rejected and Haru finally manages to reach Akiyuki and help him to recover his memory.

Raigyo and Ishuu make their final push into the chamber of the Hiruken Emperor. Nakiami and Yango leave the Tessik airship to stop the battle over the Quickening Chamber.