(from ebookjapan):

On a devastated Earth, Fantom Moly, on his way to rescue his crash-landed friends, sees...

"The 3rd era of Zethrus. Xeno is a lone sniper with the fate of the solar system on his shoulders. While waiting for the enemy, who may come at any moment, he dreams of a Japanese sniper fighting alone and helpless.

On a dimly lit battlefield, men and women put their respective pride on the line and try to survive...