Shangri-La

As a prophecy of doom unfolds on the peaceful land of Britannia, a purehearted boy sets out on a journey of discovery — and revenge.

Many years have passed since humanity was driven to the brink of extinction by the sudden emergence of the unknown life forms Gadoll. Those humans that survived now dwell in a 3000m-high mobile fortress Deca-dence built to protect themselves from the Gadoll threat. Denizens of Deca-dence fall into two categories: Gears, warriors who fight the Gadoll daily, and Tankers, those without the skills to fight. One day, Natsume, a Tanker girl who dreams of becoming a Gear meets surly Kaburagi, an armor repairman of Deca-dence. This chance meeting between the seemingly two opposites, the girl with a positive attitude who never gives up on her dreams and the realist who has given up on his, will eventually shake the future course of this world.

Arima Takuya is a young student whose father, a historian who has conducted various researches, disappeared recently. During a summer vacation Takuya receives a peculiar package from his missing father, along with a letter containing information about the existence of various parallel worlds. At first Takuya doesn't take it seriously, but soon he realizes that he possesses a device that allows him to travel to alternate dimensions. Is his father alive, after all? If so, where is he?

With Earth colonized by a superior alien civilization, Akira's only chance at a better future is to enlist as an expendable Yakitori foot soldier.