2-Shuume no Youhei wa Shizuka ni Ikirahenai

Known as the "Grim Reaper" of the battlefield, Kurona Masamune was a mercenary who could single-handedly shift the course of war in East Africa. Raised to obey without question, he lived by his father’s creed: “Have no will of your own—just follow orders.” As the perfect weapon, he served faithfully until betrayal cost him his life during a mission. But death is not the end. Kurona awakens fifteen years in the past, back in his middle school classroom. Haunted by the regret of his former life, he vows to do things differently this time. No longer a mindless tool, he now acts on his own resolve, confronting the evils lurking within his school in this tale of revenge and redemption.