Years ago, a war for Earth supremacy took place between five races, and thanks to the hero Sid, humans prevailed.
Now, it is the responsibility of a new generation to see that the sanctuaries where all kinds of monsters were sealed are not altered.
Kai is a human who takes his task very seriously, and although everything seems to be in order, he does his work every day in the company of his team.
And upon returning to his base, Kai does not stop and continues training hard. At that moment he receives a call from Jeanne, his childhood friend, who has just been promoted in rank and will leave in a few days for another city.
Jeanne is extremely devoted, almost as much as Kai, and thanks to her father’s inheritance, she has the skills and prestige to forge a career and help humanity.
Halfway through his visit to the city, something strange happens and Kai disappears before his friend’s eyes.
Upon regaining consciousness, Kai sees the city he was walking through, totally destroyed. Suddenly, a demon appears and begins to attack him.
The shrines are supposed to keep demons locked away, but now they are free, destroying everything in their path.
Before anything more serious happens, Kai is saved by his companions, but for some reason, they don’t recognize him, and say they’ve never seen him before.
Kai is taken to an underground city, where he is told that the humans lost the war and are now barely surviving.
The surprises don’t end, when he sees Jeanne walking towards him dressed in a man’s military uniform and again confirms that no one in this world can remember him.
(なぜ僕の世界を誰も覚えていないのか?)
