Senkuu has made it his goal to bring back two million years of human achievement and revive the entirety of those turned to statues. However, one man stands in his way: Tsukasa Shishiou, who believes that only the fittest of those petrified should be revived. As the snow melts and spring approaches, Senkuu and his allies in Ishigami Village finish the preparations for their attack on the Tsukasa Empire. With a reinvented cell phone model now at their disposal, the Kingdom of Science is ready to launch its newest scheme to recruit the sizable numbers of Tsukasa's army to their side. However, it is a race against time; for every day the Kingdom of Science spends perfecting their inventions, the empire rapidly grows in number. Reuniting with old friends and gaining new allies, Senkuu and the Kingdom of Science must stop Tsukasa's forces in order to fulfill their goal of restoring humanity and all its creations. With the two sides each in pursuit of their ideal world, the Stone Wars have now begun!

Tanya Degurechaff is a young soldier infamous for predatorial-like ruthlessness and an uncanny, tactical aptitude, earning her the nickname of the Devil of the Rhine. Underneath her innocuous appearance, however, lies the soul of a man who challenged Being X, the self-proclaimed God, to a battle of wits—which resulted in him being reincarnated as a little girl into a world of magical warfare. Hellbent on defiance, Tanya resolves to ascend the ranks of her country's military as it slowly plunges into world war, with only Being X proving to be the strongest obstacle in recreating the peaceful life she once knew. But her perceptive actions and combat initiative have an unintended side effect: propelling the mighty Empire into becoming one of the most powerful nations in mankind's history.

Off-duty Japan Self-Defense Forces (JSDF) officer and otaku Youji Itami is on his way to attend a doujin convention in Ginza, Tokyo when a mysterious portal in the shape of a large gate suddenly appears. From this gate, supernatural creatures and warriors clad in medieval armor emerge, charging through the city, killing and destroying everything in their path. With swift actions, Youji saves as many lives as he can while the rest of the JSDF direct their efforts toward stopping the invasion. Three months after the attack, Youji has been tasked with leading a special recon team, as part of a JSDF task force, that will be sent to the world beyond the gate—now being referred to as the Special Region. They must travel into this unknown world in order to learn more about what they are dealing with and attempt to befriend the locals in hopes of creating peaceful ties with the ruling empire. But if they fail, they face the consequence of participating in a devastating war that will engulf both sides of the gate.

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.