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?
Still, I have enough reason 
to believe you're sincere.
.لكن لديّ أسباب كافية تجعلني أصدّق إخلاصك
Aber es gibt einen Grund,
warum ich dir vertrauen könnte.
Pero sí creo que eres sincero,
aunque no puedo explicarte el porqué.
Pero sí creo que eres sincero,
aunque no puedo explicarte el porqué.
Néanmoins,
il y a quelque chose qui m’y pousse.
Comunque sia, ho valide ragioni 
per credere che tu sia sincero.
Mas tenho motivos para acreditar
que está sendo sincero.
Но у меня есть причины верить.