Gargantia on the Verdurous Planet

Gargantia on the Verdurous Planet (Suisei no Gargantia) is a 2013 anime series made by Production I.G.

In a distant future, all of mankind has apparently left the Earth, navigating through space in search of a new home. They're also engaged in a war with a group of cephalopod-like aliens. During a battle with these aliens, Lieutenant Ledo gets lost in space thanks to a wormhole along with his Humongous Mecha, falls on some primitive planet and is found by scavengers that try(but fail) to pierce the mecha apart. Chamber, an AI that serves to assist Ledo's role as a soldier and put him in artificial sleep to protect him when the accident happened, wakes him up and informs him of the situation. Soon, however, Ledo and Chamber discover where exactly they are: Planet Earth, that by this point was considered by the space-faring humans to be some kind of myth.

Now stranded on Earth, unable to contact his superiors, and with only a primitive translator allowing him to communicate with the humans on Earth, Ledo will have to try to coexist with the inhabitants of the fleet ship where he is now. And Earth hasn't become a pacific planet, oh no....


 * Ambiguously Gay: The pirate queen for some reason keeps two skimpily dressed girls in chains around her throne.
 * Artificial Gravity: How Ledo's Mecha moves, by apparently using a spherical object near the head of the robot to generate gravitational waves instead of some kind of propeller or jet.
 * Cycle of Revenge: The reason why Gargantia's inhabitants don't like Ledo terminating the pirates that attacked them, because this will motivate pirates from the same crew to attack with lethal force as revenge.
 * Foil: Amy and Ledo were basically made to be opposite. Ledo's hair and eye colour are neutral, his clothes are in dark colours, he lived on artificial environments until now, his Non-Human Sidekick is a cold, calculated robot, and his mood is usually "stoic". Amy has shiny blue eyes, brown hair, her clothes are in vivid colours, she lived her whole life surrounded by nature, her Non-Human Sidekick is a adorable squirrel, and she is anything but stoic, whether she is happy, sad, or angry.
 * Happiness in Slavery: The pirate queen's slaves willingly assist her in battle.
 * Humongous Mecha: All humans have access to them, but the ones of the Alliance are clearly superior to the ones on Earth in all aspects of attack or defense or reach, and also come with their own artificial intelligence smart enough to translate languages that they never heard before to an acceptable level of comprehension.
 * Ill Boy: Subverted. Amy's little brother is paraplegic and seems to live in his bed, but otherwise he seems healthy and optimistic like any other child.