Humans have been polluting the ocean for a long time, carelessly pouring their garbage and desecrating the waters that many creatures call home. The denizens of the sea have suffered at their poisoning hands. Finally, one certain squid has had enough and vows to punish the humans' selfish actions. Possessing all the fearsome abilities of a squid such as powerful hair-tentacles, the ability to spit ink, and even use bioluminescence at will, Ika Musume takes it upon herself to rise from the depths of the ocean and exact revenge upon humanity! She surfaces at a certain Lemon Beach House, a restaurant managed by the sisters Eiko and Chizuru Aizawa. Thinking them to be an easy first step toward world domination, she immediately declares war against them, only to find out that she is, quite literally, a fish out of water! To make things worse, she destroys a part of a wall of the beach house in an attempt to flaunt her squiddy superiority and is consequently forced into becoming a waitress to pay the repair costs. Beached for the time being after tasting a thorough defeat at the hands of the Aizawa sisters, Ika Musume is forced to put her plans for world domination on hold. Despite these setbacks, Ika Musume soon finds herself right at home in her unexpected position as Lemon Beach House's newest employee. Wacky and hilarious, Shinryaku! Ika Musume follows her brand new life on the surface as she makes precious memories and meet lots of new people. With her newfound acquaintances, Ika Musume is looking to take the world by storm, one squid ink spaghetti at a time! [Written by MAL Rewrite]

The Seven Deadly Sins, along with Elizabeth Liones and Hawk, have won the Kingdom of Leones back from the Holy Knights. At long last, it's their time to indulge in the peaceful lives they fought for. From inedible meat pies, overdue battles, unexpected stalkers, and the butterflies of first love, the Sins are accompanied by their friends in their carefree, fun-filled time together. However, the calm is broken with the premonition of a new threat, bringing upon the signs of Holy War and threatening to shatter the peace of the Sins' easygoing days. [Written by MAL Rewrite]

Equally charming and stern, Heine Wittgenstein is a brilliant man who commands respect, despite his short, childlike stature. Thus, the king of Grannzreich has called upon Heine to undertake a daunting task that has driven away many before him—become the new royal tutor to four princes who are in line for the throne. The four heirs each have very distinct and troublesome personalities: Licht, the flirtatious youngest prince; his immature older brother Leonhard; Bruno the studious third prince; and Kai, the oldest of the four and the most reserved. Hilarity ensues as Heine attempts to connect with each of the princes in order to groom them for the throne. However, Heine's mysterious past and dark undercurrents in the present may threaten the harmony within the kingdom. [Written by MAL Rewrite]

Episodes that were only released on the DVD afterwards and didn't air on TV. Episode numbers: 7.5, 9.5, 10.5, 12.5. For a complete list of episodes and the order they're included in the Kamichu! DVD/BD box set, see the More Info tab.