Yuka, a neat lady who usually goes to an all girls school. But behind her façade is here identity as "lady detective" who fights against an evil organization that shakes peace. Yuka fights for world peace, swayed by her school romance and friendships. Creating a group of femme fatales to help her along the way to help her fight this evil cultist organization.
Three computer-savvy kids, Naoto, Yuka and Ippei created their own videogame superhero, but then discover it possessed by an inter-dimensional police officer, Gridman. Pursuing an evil program called Kahn Digifer, he merges with Naoto and fights Kahn Digifer's digitized monsters in order to prevent the computerized demon from wreaking havoc on the Human World.
After the defeat of the demon lord Hadlar all of the monsters were unleashed from his evil will and moved to the island of Delmurin to live in peace. Dai is the only human living on the island. Having been raised by the kindly monster Brass, Dai's dream is to grow up to be a hero. He gets to become one when Hadlar is resurrected and the previous hero, Avan, comes to train Dai to help in the battle. But Hadlar, announcing that he now works for an even more powerful demon lord, comes to kill Avan. To save his students Avan uses a Self-Sacrifice spell to attack, but is unable to defeat Hadlar. When it seems that Dai and Avan's other student Pop are doomed a mark appears on Dai's forehead and he suddenly gains super powers and is able to fend off Hadlar. The two students then go off on a journey to avenge Avan and bring peace back to the world.
A high school girl, Izumi Gojo, who has been found guilty of murder, falls into the sea and disappears when running away from the police. However, a mysterious group rescues her and had her undertake training to transform her into an assassin. Years later, Izumi seeks to escape the group.
The plot of the series revolves around three youkai, Bem, Bera and Barro, who arrive at a large coastal city and come across an evil atmosphere, which was brought about by immoral behavior by humans and mischief caused by monsters and youkai. They therefore decide to stay in the city, fighting against other monsters and yōkai which attack humans, making a few friends in the way. Even though the three youkai are often abused by other human beings due to their appearance, they still strive in protecting the human populace of the city from other monsters, one day hoping to become human beings in return for their good actions.
