Elemental Gelade- Aozora No Senki

The Kingdom of the Sun, Fuajarl was ruthlessly invaded by the Garden of Eden. They came seeking the King's Edel Raid, rumored to be one of the Seven Glittering Jewels (or Shichiko-hoju). Sensing their intent, the King hid his daughter with his Edel Raid and fought against the invasion but was defeated in battle that resulted in the desert kingdom being blanketed in a sheet of white snow. Escaping capture, the Crown Princess Achea Fuajarl XIV reacted with Jeen, the King's Edel Raid, and along with Puffe, the Kingdom's only mechanic, fled Fuajarl in an ancient tank. They are on a journey to restore the Kingdom and exact vengeance on the Garden of Eden. This story takes place two years after Erementar Gerad.