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?
Sorry. Guess I'm just casual 
to the point of being annoying.
.آسف. أعتقد أنني غير رسميّ لدرجة مزعجة
Tut mir leid. Bin anscheinend
viel zu lässig drauf.
Lo siento. Suelo ser algo confianzudo.
Lo siento. Pillo confianza rápidamente.
Désolé, on me dit souvent
que je suis trop familier.
Mi dispiace. A quanto pare,
 sono un tipo un po' troppo sfacciato.
Foi mal. Parece que não sou
de fazer cerimônias.
Извини, не хотел фамильярничать.