from Squid Girl
Origin
The Ocean
Squid Girl (Ika Musume) is a humanoid squid girl who came to land with the goal of taking over it and is the main protagonist. Squid Girl was hatched into the Ocean near Japan and lived there for an unknown amount of years. But when humans started littering the sea she came to land with the goal to take over it in revenge. Her main goal was to make them pay for dirtying the ocean with their garbage, but accidentally blew a hole in the Lemon Beach House, which was owned by Chizuru, Takeru and Eiko. In order to pay back the money for the repair she started working at the Beach House, while trying to take over Earth.

Squid Girl
The sea in our world has been polluted. All sorts of trash were thrown into the sea, making it unpleasant deep under the sea. One of the inhabitants of the sea, Ika Musume (Squid Girl) seeks to exact revenge on humanity for throwing trash into the sea. Clueless about the surface, she seeks to invade humanity alone, trying to rule over the world, only to find herself slaving away at one of the nearest beach-houses for breaking a side of its wall.