Fourteen-year-old Iruma Suzuki has been unfortunate all his life, having to work to earn money for his irresponsible parents despite being underage. One day, he finds out that his parents sold him to the demon Sullivan. However, Iruma's worries about what will become of him are soon relieved, for Sullivan merely wants a grandchild, pampering him and making him attend the demon school Babyls. At first, Iruma tries to keep a low profile in fear of his peers discovering that he is human. Unfortunately, this ends up being more difficult than he expected. It turns out that Sullivan himself is the chairman of the school, and everyone expects him to become the next Demon King! Iruma immediately finds himself in an outrageous situation when he has to chant a forbidden spell in front of the entire school. With this, Iruma instantly earns a reputation he does not want. Even so, he is bound to be roped into more bizarre circumstances. [Written by MAL Rewrite]

A.D. 2040—Thirty years have passed since the battle between the Earth and Zentraedi forces changed the lives of both races. On planet Eden, a top-secret project known as "Supernova" is being held to determine U.N. Spacy's next-generation variable fighter. Competing to win the funding are Shinsei Industries' YF-19 and General Galaxy's YF-21. Piloting the YF-21 is Guld Goa Bowman, a half-human, half-Zentraedi. Shinsei receives its new test pilot in the form of the unruly fighter pilot Isamu Dyson, who was once a friend of Guld. Meanwhile, as Isamu and Guld furiously battle to see which of their fighters is superior, a Virturoid Idol named Sharon Apple is to perform her debut concert on Eden. In charge of Sharon is producer Myung Fang Lone, another former friend of Isamu and Guld. When the three meet each other, old disputes spark from a troubled past. Little do they know that their past incidents—along with the Supernova Project and Sharon Apple—will somehow bring them together.

Kyou kara Maou! revolves around Yuri Shibuya, your average Japanese teenager. One day, Yuri sees a classmate being harassed by bullies. Thanks to this intervention, his friend is able to escape, but unfortunately Yuri becomes the new target of the bullies in the process and gets his head shoved into a toilet. But instead of water, the toilet contains a swirling portal that sucks him into another world, largely resembling medieval Europe. There, he is told that he will become the next Demon King due to his black hair and black eyes, traits only possessed by the demon's royal lineage. Yuri's arrival is met with some skepticism by some of the demons, who view him as unworthy to be their king. However, after Yuri wins a duel by utilizing his magical powers, the demons slowly begin to acknowledge him as their monarch. Yuri must now learn what it takes be a true Demon King, as he tries to keep the peace between demons and humans in this strange new realm.

Unsuspecting inhabitants of the planet Earth are going about their business, enjoying a bright and particularly beautiful sunny day, when a young Japanese boy spots a shiny object falling from the sky... Has an alien invasion finally begun? Elsewhere in Japan, Keroro, frog sergeant and leader of the Space Invasion Army Special Tactics Platoon of the 58th Planet in the Gamma Planetary System, has discovered the perfect hideout. He infiltrates the home of the Hinata family in an attempt to establish a headquarters that he and his troops could use to prepare for world domination... but earthlings Fuyuki and Natsumi Hinata are too much for him to handle! Natsumi instinctively calls them out of hiding, leaving the hapless sergeant no option but to reveal his secret identity. The two siblings soon welcome the sergeant to their home, all thanks to Fuyuki’s generos—err... curiosity. The Sergeant has successfully infiltrated his first target area! Or has he? Join Keroro Gunsou in his dastardly attempt to take over the world!