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?
Do you think a spy would go to the trouble 
of trying to convince you of this?!
!هل تعتقدين أنّ جاسوسًا سيتكبّد عناء محاولة إقناعك بهذا؟
Glaubst du etwa, ein Spion würde
dich davon extra überzeugen wollen?!
¡¿Qué espía intentaría
convencerla de esto?!
¡¿Qué espía intentaría
convencerla de esto?!
S’embêterait-il
à essayer de vous convaincre ?
Una spia si prenderebbe il disturbo
di cercare di convincerla di questo?!
Acha que um espião teria
tanto trabalho pra te convencer?
Разве шпион выбрал бы 
такой абсурдный путь?