Surrounded by four armies of dark beasts, five humanoid races strive to push the known boundaries of the world. Unfortunately, the 13 heroes dispatched to the southern region are easily wiped out by Clevatess, one of the Lords of Dark Beasts. Determined to get revenge against humanity, Clevatess bursts into the capital of the Kingdom of Hiden, leaving a trail of death and destruction behind him. Although the situation looks desperate, humanity still has a chance to appease Clevatess' anger. Alicia Glenfall, one of the 13 heroes, is revived by Clevatess to help him raise a newborn infant, Luna, whose choices shall shape the fate of the human world. Although reluctant to help the dark beast at first, Alicia understands that Luna is the only thing that stands between humanity and complete annihilation. Hiding himself by taking on a human form, Clevatess sets out in search for a wet nurse with Alicia and Luna. With Clevatess unwilling to reveal his identity, it falls on Alicia to slay all enemies that stand in their way. Meanwhile, the neighboring countries prepare to advance on the weakened Hiden, aiming to control the only forge capable of producing the heroes' weapons.

High school first year Yuu Yuutani has always been a good girl, following the rules, helping out around her house, and generally going through life unnoticed. From afar, she reveres her upperclassman and the school's Public Decency Officer, Atori Mizutori, and desperately wants her attention. When she realizes that the best way to get Atori to notice her is to be a delinquent, she begins to dress differently: she dyes parts of her hair a bright red, wears clips on her ears to resemble piercings, and attaches jumbo erasers to her shoes to give them thicker soles. Despite Yuu's best efforts and even with the advice of her "natural born delinquent" friend Suzu Suzukaze, all of her plans to be a bad girl go awry. Still, Yuu manages to befriend Atori and pledges to spend as much time as possible together, not knowing there are others vying for Atori's attention. In the process, Yuu has also gained the attention of the school's self-proclaimed idol, Rura Ruriha, filling her once-invisible life with more attention than she may be able to handle.

A virus spreads across the world, transforming all humankind into wild, slavering, furry beasts: cats, to be precise. Those few survivors who remain human take refuge in the dark corners of the earth as they fight back against the feline horde. Kunagi, a man with no memory of his past yet a deep knowledge of cats, struggles to hold on with only his wits and a will to survive. Yet the virus transmits merely through cuddles, and Kunagi finds kitties so hard to resist! Is his willpower strong enough to withstand this hair-raising cat-tastrophe?

Mogura, a mysterious "self-proclaimed sage" also known as Hyakuan Momoyumi, has been banned from the afterlife. To return, he roams the world, collecting the "lamps" of ghosts in his lantern. However, crossing paths with him brings an unusual consequence: the ability to see strange phenomena...