Megumin is a young and passionate wizard from the Crimson Demon Village, a remote community of mages with red eyes and a flair for the dramatic. She has devoted her life to mastering explosion magic, a powerful but impractical spell that leaves her drained of mana and unable to move for the rest of the day. Regardless, she refuses to learn any other skills. Along with her childhood friend and self-proclaimed rival, Yunyun, Megumin enrolls in the Red Prison: a prestigious academy for Crimson Demon magic users. There, she learns more about the secrets and history of her clan, as well as the threats and challenges they must face. As she polishes her power at the Red Prison with the help of her loyal familiar Chomusuke and her adorable little sister Komekko, Megumin aims to become the greatest explosion wizard of all time!

In the near future, humanity has taken its first steps towards journeying into the far reaches of the galaxy. Upon doing so they discover a huge race of insectoid aliens known as "Space Monsters." These aliens seem dedicated to the eradication of mankind as they near closer and closer to discovering Earth. In response, humanity develops giant fighting robots piloted by hand-picked youth from around the world. Shortly after the discovery of the aliens, Noriko Takaya, the daughter of a famous deceased space captain, enters a training school despite her questionable talents as a pilot. There, she meets her polar opposite, the beautiful and talented Kazumi Amano, and is unexpectedly made to work together with her as they attempt to overcome the trauma of war as well as their own emotions.

Mini-OVA specials bundled with each Blu-ray/DVD volume of Kenzen Robo Daimidaler.

Battles continue between "Penguin Empire", the mysterious life form which arrived on earth all of a sudden, and "Beauty Salon Prince", the secret anti-Penguin organization. In order to fight Penguin Empire's gigantic "Penguin Robot", Beauty Salon Prince has developed their ultimate weapon, "Daimidaler", and is now looking for the pilot. They choose Koichi Madanbashi, a hot-blooded high school boy who is mad about big boobs, because he is the factor of "Hi-ERo particles", the source of unknown energy.