Shirogane Takeru found himself inexplicably transported to a world that resembled his own in many ways, with one major difference: For nearly 30 years, mankind has been at war with the alien BETA, who have succeeded at wiping out over half of humanity and had nearly captured the entire Eurasian continent. As Takeru tried to come to grips with this bizarre new reality, he realized too late that the majority of humanity will be abandoned with the Earth, as the chosen few escape to the stars, hoping to find sanctuary.

Now, equally inexplicable reasons, he finds himself returned to the first day of his time in this alternate world. Will the experiences and knowledge he has gained allow him to make a difference?
And the people I knew from my world 
were there, but they were different.
.والأشخاص الذين عرفتهم من عالمي كانوا هناك لكنهم مختلفون
Und die Leute, die ich aus meiner Welt kannte,
waren auch da, doch sie waren anders.
Y aunque estaba la gente de mi mundo,
no eran los mismos.
Y aunque estaba la gente de mi mundo,
no eran los mismos.
J’ai retrouvé mes connaissances,
mais leur statut était différent.
E le persone che conoscevo nel mio mondo,
 qui erano diverse.
E as pessoas que eu conhecia no meu mundo
estavam lá, mas tinham posições diferentes.
И там были знакомые мне люди,
 но уже другие.