Black Bullet, Vol. 4 (manga) (Black Bullet (manga), Band 4)

Humanity continues to fight for its right to a future. Rentaro's enemy is the sinister Kagetane Hiruko, but there's another threat-a gigantic Stage Five Gastrea that threatens to destroy everything Rentaro has worked to protect. Overwhelming odds demand unthinkable sacrifices, but sometimes even that may not be enough...