In Re:Monster, Tomokui Kanata is unexpectedly reincarnated into an alternate world as Goburou, the weakest goblin, after an unfortunate death. Even in this new body, he keeps the memories of his former life, and that unusual advantage lets him adapt quickly to a brutal setting where only the strong survive. Goburou also undergoes a strange evolution: the more he eats, the more he grows, eventually becoming strong enough to gain status boosts from eating.
As Goburou struggles to stay alive, he learns to make the most of his memories, instincts, and the harsh rules of his new environment. The story follows his rise through a world defined by survival of the fittest, where every encounter can mean death or a chance to evolve. Along the way, he is joined by competent subordinates and comrades, and what begins as the journey of a weak goblin slowly turns into a curious, delightful case of the tail wagging the dog.