In the far-distant future, mankind has moved to the stars and formed the Galactic Alliance of Humankind. The GAH has been fighting a long war with a squid-like alien race, the Hideauze.
Ensign Ledo, a 16-year-old AI battlemech pilot, is just one battle away from a one-month vacation.
Yet to earn it, he and his AI battlemech must survive a surprise attack on an enemy super weapon. During the attack, Ledo is knocked into a wormhole. He wakes up to find himself on Gargantia, a large floating city made up of old ships. What's more, the planet he is on turns out to be the long-abandoned planet Earth.
The 12-episode show has just finished its run in Japan, but can still be found on the live streaming site, Crunchyroll. The Japanese Blu-ray disc release of the first four episodes will include English subtitles and a 14th episode OVA, making it very worthwhile, since the North American distributor VIZ Media has announced a 2014 release date on disc and live streaming on Hulu.