After his unfortunate death, Tomokui Kanata has been reincarnated as a member of the weakest race, a goblin named Rou. However, Rou has retained his previous life's memories, as well as an ability that allows him to gain strength and abilities from eating. He also possesses a unique evolutionary tree. Now, Rou has made a promise to himself that he would live this life to the fullest. In this alternate world of survival of the fittest, events unfold with competent subordinates and comrades.