Squid Girl and Eiko pair up to join the beach volleyball tournament. With sights set on the grand prize of a 3D TV, the usual faces stand in their way: Sanae and Cindy, Gorou and Isozaki, Nagisa and Kiyomi. Even the owner of the South Wind and the Idiots Three enter as the matches become chaotic! Squid Girl's tentacles stop working. Various treatments to restore them are unsuccessful and Squid Girl is at a loss. Finding the flapping things on her head also won't move and even her ink is weak, Squid Girl makes the decision to... With no prospect of restoring her tentacles, Squid Girl has lost both her invader self and her pride as a squid. Suddenly before her appears...?

Eiko takes out a doll that she treasured as a child. Squid Girl is creeped out by the rotten doll's weird appearance, but Eiko says she will put it in her room for nostalgia. That night, Squid Girl can't help but notice the doll's stare from the shelf and turns the doll around. However... Cindy and the Idiot Three, who are always wandering about looking for aliens, make Chizuru their next target after Squid Girl. Her superhuman abilities has them suspecting her of being an alien. The Idiot Three immediately try to get near Chizuru to use various inventions to obtain samples for testing such as blood and hair... The members of the Lemon challenge Squid Girl to go mountain climbing with them, but she doesn't understand the fun of climbing so the path is nothing but pain. Tired of walking, she tries to extend her tentacles to cheat, but they are bitten by mountain wildlife. Squid Girl tries to shake off the wildlife who has mistaken her tentacles for bait, but...

Wishing for sunny weather so he can go out and sketch for his homework, Takeru makes a teru teru bozu. Being told that since he's in this situation, he should draw what's here, Squid Girl says she will help. After taking the pen for herself, everyone is shocked at the outcome of the image she drew! Sanae attempting to embrace Squid Girl and harshly getting smacked away has become a daily sight. Eiko worries about this unhealthy behavior in Sanae and urges her to abstain from Squid Girl. She inspires Sanae by telling her it will get Squid Girl to like her, but it's self-torment beyond her imagination. The pitcher for Kiyomi's baseball team falls ill just before a practice game. Squid Girl says she will play as a substitute on short notice, but not knowing the rules, she makes defensive errors immediately. Moved by Kiyomi's kind words and encouragement after her errors, Squid Girl demonstrates the power of a squid!

Squid Girl pushes the doorbell at a stranger's house as a prank. She tries to flee immediately but she runs into Chizuru and then the occupant of the house comes out. She feigns as if she's there to visit a friend to try to deceive them, but she is in a critical situation as then Kiyomi shows up, having returned from club activities! Squid Girl has the lipstick she got from Eiko applied by Chizuru. She is impressed by her new look and decides to work at the Lemon while looking like that. Not discouraged by an attack from an over excited Sanae, Squid Girl is unable to control her curiosity about make-up and wants to try out various styles, except... The three stooges from Cindy's lab come to the Lemon. They pull out various inventions that they brought from the lab, but they all look really shady. Among them, Squid Girl wants to try out the "bullets that grants you the dignity of an invader," but the light fired from the gun causes...!?

#1 Squid Girl is passing by a hero show and decides to observe the show with the excited children. After the Black Tights attack the children, in the usual plot twist, the hero known as the Noh Mask Rider appears. The strange looking hero causes Squid Girl to fall over laughing, but when the boss, the Squid Demon appears, her expression does an about-face! #2 Squid Girl gives the answer to a math problem Eiko was agonizing over from behind her. Eiko suspects she somehow cheated, but she correctly answers all the additional problems she is given. Unable to accept this, Eiko gives her the ultimate obstacle of a college entrance exam problem. Squid Girl writes down a number of formulas... #3 Nagisa is swallowed by a giant wave while surfing and is saved by Goro. The next day, Goro comes to the Lemon where Nagisa is able to thank him again for saving her, but...

Cindy, the bikini-clad beauty with streaming blond hair, is here from America to get information on alien sightings. Seeing Squid Girl, Cindy decides she is an alien and tries to take her back to the laboratory. Squid Girl resists and uses her tentacles and squid ink to try and prove she is a squid, but this is evidence of an alien to Cindy and ends up only further convincing her!? Eiko is heading to high school for a school day during summer break causing Squid Girl to be very interested in what kind of place "school" is. Worried about a disruption, Eiko makes it clear to Squid Girl that she is to be at the Lemon before departing, but she spots Squid Girl at school! Investigating the chemistry lab, the home-ec room, and the gym storehouse, Squid Girl is convinced "school" is a human army base! Eiko is taking a stroll on the beach when she hears something crying. Looking at the water's edge, she finds a small creature struggling inside of a bottle. Eiko takes the bottle and the small creature inside of it home...

#1: Squid Girl receives 10,000 yen as thanks for finding a wallet lost in the sand. Having no idea about the value of money and with Nagisa accompanying her, she goes to the shopping district. Not knowing what to buy, she jets back and forth. In the end, she buys a ton of her beloved shrimp, but Sanae has been watching the two shop from the shadows... #2: After business hours at the Lemon, Squid Girl wants to go home with with the Aizawa family, but Eiko obstinately refuses to let her. With no choice, Squid Girl goes to pass the time in front of the TV at the Lemon, but it breaks. With time to kill, she amuses herself playing squid-vasion with some accessories... #3: Squid Girl and Eiko have come to the neighboring beach to investigate and encounter a fake Squid Girl, bikini clad with a Squid Girl like head. The owner of the South Wind House at the Sea has built a fake which discharges a black liquid from its mouth and can move its tentacles. Wanting to exchange the fake one for the real one, he challenges them...

1: Squid Girl watches a TV special on ghosts but isn't frightened at all. The gang decides to show her some real ghosts to finally get her scared, but things don't go quite as planned... 2: Takeru and Squid Girl are swimming in the ocean when they come across her natural sworn enemy, the orca. However appearances can be deceiving... 3: Nagisa joins as a new part time worker at Lemon House at the Sea. She is super excited about being able to be near the beach, as her passion is surfing, but she becomes terrified of Squid Girl's appearance...

When her tentacles cramp, Squid Girl is saved from drowning by the lifeguard Goro. Hearing the lifeguard's job is to protect the sea, Squid Girl feels a sense of comradery. However, in reality his job is different from what Squid Girl, who plans to subdue humanity, imagines. Screwing with his work), an opportunity for her planned revenge on the Goro appears before her, but... 2: Squid Girl, having taken interest in some humans celebrating a birthday party, sets her own birthday and demands that they hold a party for her. Chizuru graciously decides to hold the party immediately and begins to prepare with the other members of the Lemon. But when Squid Girl sees this, she...? 3: Eiko's classmate, Sanae, brings her dog Alex to play at the Lemon. Being jealous of how Eiko dotes on Alex, Squid Girl demands the same treatment, (but is unintentionally handled with like an actual dog) by Chizuru. Seeing this, Sanae invites Squid Girl to her house. However...

1) The Aizawa sisters run the business at the sea "Lemon" where they serve beach goers. During their busiest hour, a strange girl appears before the younger sister Eiko. A hat with three points, wavy, water-colored hair, and a white one-piece suit. She calls herself Squid Girl and claims to be a messenger from the sea who's come to subdue humanity. When Eiko tries to dismiss her ludicruous speech, she unleashes the wrath of Squid Girl. 2) Squid Girl is stuck working for the house at the sea "Lemon". Being worked so hard, she feels down when a shadow creeps up on her. When she tries to run from that shadow, her tentacles are grabbed. When she turns around, she sees a boy's face, full of curiosity. 3) Due to the rain, the Lemon is deserted. Because of the chill, Squid Girl sneezes and covers the older sister Chizuru in a black liquid. When Chizuru licks this liquid... She realizes it's tasty tasty squid ink. When Squid Girl finds out that humans eat spaghetti mixed with squid ink...