Fifteen years have passed since the war between humans and demons began. Dissatisfied with their slow advance into the Demon Realm, the Hero abandons his companions to quickly forge ahead towards the Demon Queen's castle. Upon his arrival at the royal abode, the Hero makes a startling discovery: not only is the Demon Queen a woman of unparalleled beauty, but she also seeks the Hero's help. Confused by this unexpected turn of events, the Hero refuses to ally himself with his enemy, claiming that the war the demons have waged is tearing the Southern Nations apart. However, the Demon Queen rebuts, arguing that the war has not only united humanity but has also brought them wealth and prosperity, providing evidence to support her claims. Furthermore, she explains that if the war were to end, the supplies sent by the Central Nations in aid to the Southern Nations would cease, leaving hundreds of thousands to starve. Fortunately, she offers the Hero a way to end the war while bringing hope not only to the Southern Nations, but also to the rest of the world, though she will need his assistance to make this a reality. Finally convinced, the Hero agrees to join his now former enemy in her quest. Vowing to stay together through sickness and health, they set off for the human world. [Written by MAL Rewrite]

On a rainy afternoon, a male high school student awakens freezing on the streets with no memory of how he got there. His classmate and crush, Karen Inukai, finds him and takes him back to her home where, to his surprise, she starts to undress. She seems intent on bathing with him, though he has no idea why. When she holds him once more, he catches a glimpse of himself in the mirror—discovering that he has turned into a dog! Inukai adopts the puppy and names him Pochita. Now, he must adjust to life as a dog and figure out how to get out of this strange predicament. But while he mulls over an escape plan, Pochita sees a whole new side to Inukai that he never saw at school.

Several months have passed since the infamous Ginza Incident, with tensions between the Empire and JSDF escalating in the vast and mysterious "Special Region" over peace negotiations. The greed and curiosity of the global powers have also begun to grow, as reports about the technological limitations of the magical realm's archaic civilizations come to light. Meanwhile, Lieutenant Youji Itami and his merry band of female admirers struggle to navigate the complex political intrigue that plagues the Empire's court. Despite her best efforts, Princess Piña Co Lada faces difficulties attempting to convince her father that the JSDF has no intention of conquering their kingdom. Pressured from both sides of the Gate, Itami must consider even more drastic measures to fulfill his mission. [Written by MAL Rewrite]

Nierland—an A.I complex theme park where dreams, hopes, and science intermingle. Created as the first-ever autonomous humanoid A.I, Vivy acts as an A.I cast for the establishment. To fulfill her mission of making everyone happy through songs, she continues to take the stage and perform with all her heart. However, the theme park was still lacking in popularity. One day, an A.I named Matsumoto appears before Vivy and explains that he has travelled from 100 years into the future, with the mission to correct history with Vivy and prevent the war between A.I and humanity that is set to take place 100 years later. What sort of future will the encounter of two A.I with different missions redraw? This is the story of A.I destroying A.I. A.I diva Vivy's 100-year journey begins. (Source: MAL News)