Ika Musume is the animated film Invasion! One of the heroines in Ika Musume and its derivative works, the marine human who hates pollution most, decided to swim ashore and occupy the land, so she decided to occupy the sea house "Lemon" in the bathing beach as a stronghold for invading the land. Unexpectedly, before the invasion, Ika Musume was forced to work in Lemmon to pay off his debts. Although his aggressiveness never wavered, he gradually got used to this land, began to like human beings and finally became good friends with them.