Ouka stumbles upon a "young girl" stealing an apple one day, per chance, to find himself part of the "Cozy Family Operation" - a top secret mission, in which he has to take the place of father for an abnormal family, in order to find the child of Enka, who is destined to destroy the world.
While Kyouka is busy dreaming about the perfect wedding for her and Ouka, Yuuka is having a hard time fitting into school. In order to resolve the problem, Kyouka jumps into a mother's shoes, and so, in the middle of Yuuka's gym lesson, the frenzied family perform a short play, and successfully make Yuuka appear like a magical girl. Meanwhile the culprit behind the bullying is revealed.
The bullying is yet to cease, and so, Yuuka comes home crying one day, to be comforted by Ginka. The family express their concerns, especially after it appears Teika and Hyouka are ready to do some serious about the situation. The next day, Yuuka is confronted by a teenage girl - her biological sister, Senko, who has come to take her younger sister back. The truth regarding Yuuka's previous family is revealed - her family traditionally tortures the youngest daughter - Yuuka - for being a demon. Before the situation gets out of hand, Ginka appears, and apparently knows Senko. Night comes, and the bullies are at it again, this time aided by Senko, who is madder than ever before, claiming she needs to be saved too. Ginka's second arrival spurs this, as Senko wakes up in the Midarezaki household. Kyouka threatens to kill Senko for being an enemy of the family, but Ouka jumps in and pulls her away.
Kyouka discovers that married couples go on honeymoons prior to their marriage, and so, begins to book one, with help from Chika, who sees it as an opportunity for her and Ginka to get together.
Kyouka builts an airport outside of the Midarezaki family household, so the family can head off to the honeymoon without too much fuss. The family become good friends with a boy nicknamed "Pierre", however, their hotel resort is dangerous, and thus, Yuuka is kidnapped by a group of evil monkeys.
The family, in an attempt to save Yuuka, entice the monkeys of the island with free food and a huge party, while Yuuka becomes friends with the mad doctor of the island, who later turns out to be one of Hyouka's many creators.
Shu and Tsubaki were born in a family of assassins, however, Shu desperately wants to be a chef. The problem is, his food kills who ever eats it. Fortunately, Yuuka, Tsubaki's classmate, and the rest of her wacky family, are determined to get to the bottom of why the food kills everyone, and make sure that Shu's restaurant lives another day.
Ouka is on a date with an old friend of his - a Death God who mercilessly tried to kill him while they were children. Their date is briefly interrupted by Kyouka, and later the rest of the family, while all the cameras that surround them become possessed by a bunny-eared girl called "Ei".
Kyouka's past is briefly explained in this episode, as Ei brutally tries to kill her and Ouka. At the end of the episode, Ouka is stabbed by the possessed Death God, who reveals an ugly bruise on her eye. At the end of the episode, all is well, however, Ei is somewhere, seeking revenge.
Mujaki is a kind pirate, who's deceased father left her a treasure map. Kyouka wants the treasure, however ends up getting kidnapped. The family head out to sea to save Kyouka, but end up getting washed up in a cave, where the treasure is held.
Hyouka meets a girl he called "Musume-san", and the two strike up an unusual friendship. Ginka claims that this must be Hyouka's first love. However, the relationship is threatened, when everyone discovers that Musume-san's sister was killed by Hyouka, against his will.
Prior to the beginning of the story, Ginka's next door neighbour picks up a cat, to find that it has turned into a young girl by morning. The episode details their love story, with Ginka as a side character, dressed entirely as a woman through the course of the episode.
Chika goes to school, however a bunch of classmates ask her help to solve the disappearances of several classmates. Kyouka appears to help and they discover that the reason behind the disappearances was a drug developed by the mafia that turned people into animals. In the end they are saved by a green version of Hyouka and confront the true mastermind of the plan, a experience created by the department of supernatural affairs known as Electric butterfly.
The Electric butterfly having planned the catastrophe turning humans into animals, releases Dr. Gebock in order to test the Miderazeki family's potential as a weapon. Hyouka utilizes the Lucifer Cannon to save his family. Chika gets the credit for saving everyone at school.
Kyouka clumsily tries to use a magic wand from the Electric Butterfly and punish Ouka for forgetting that it is their anniversary. The wand attacks whoever the person is thinking about with a severity equal to their love however Kyoka ends up zapping everyone but Ouka and in the end she destroys the wand after it tryed to kill Ouka.
Teika sacrifices himself to save the female lion madara from the hunter. Gekka heals him. The humans and lions negotiate a peace to live alongside the wild animals without hunting each other.
When Ouka becomes sick the house falls into chaos without his reason and guidance, so the family track down a mask that might heal Ouka but in the end curses him, so they are forced to shrink and fight his disease from inside his body.
A bumbling demon tries to kill the family with a bomb but she has second thoughts when she observes the love the family has. Hyouka must face his feelings for Musume-san once again as she works at the hot spring and sauna. Chika and Ginka engage in S&M in Chika's ongoing quest to turn Ginka heterosexual.
When Chika gets bitten by a hamster she has flashbacks to memories of her first pet, a gigantic demonic monster which is actually just a cursed man. Although Chika tried to use him against the House of Oni he refused. When soldiers attack Chika searching for this monster she finds out there are connections between her first pet and her new best friend Hijiri.
When Santa Clause's granddaughter becomes depressed that grandpa never spends Christmas with her Kyouka makes the family deliver presents and take over Santa's duties while she beats Saint Nick into submission to convince him he needs to think of his own family as well as others.
Electric Butterfly warns the family of an Alien who looks weak but could destroy the world. When a female alien named Oasis comes to earth in search of the meaning of the word Love. The family members try to show her so she will leave but coincidences make everyone think Ouka is having an affair with her.
Oasis was not who Electric Butterfly was reffering to when she talked of a weak looking alien who could destroy the world. So when an alien invasion kicks off and a bumbling lovestruck alien of immense power comes to earth after a millenia of waiting... for Gekka's hand in marraige. Gekka is preoccupied with something else.
Oasis is revealed to be of a species spawned by Gekka thousands of years ago. Meanwhile Gekka must stop her offspring who want to rebel against her for abandoning them with only the lonely alien as their God. The family meets a worshipper of Kyouka who is unbeknowst to them possessed by a child of Gekka. Chika and Yuuka's big sister is revealed to be Electric Butterfly's boss and declares war on the all powerful bumbling alien.
Since the children of Gekka would die without Gekka they seek to punish her by destroying the family and earth she loves. The family must also stop her bumbling alien from destroying the earth as he is attacked. An evil waterspirit spawn of gekka possesses Kyouka.
