After being killed by a childhood friend turned yandere in his original futuristic, sci-fi world, the ESPer Tomokui Kanata was reincarnated in a different primitive, fantasy world as one of its weakest species, the Goblin. Given a second chance at life, the newly reborn and renamed Goburou swears to make the most of it. Still in possession of his memories and intelligence of his previous life, as well as his original ESPer ability, 【Absorption】, Rou quickly matures.
Thanks to his mature mind and ability, Rou has proven himself superior to the other Goblins, and at their request he starts to train them. Showing rapid growth, Rou and his closest subordinates, Kichi and Mi, had quickly ranked up to Hobgoblins. Rou then decides to lead the Goblins, growing quickly as he learns new abilities.
E, another of Rou's subordinates has Ranked Up. The senior generation of the community, who had left in order to become stronger, have returned, bringing with them five Human women whom the Goblins intended to use to breed. However, since doing this would ruin Rou's plan to help raise the strength of the community, Rou chose to challenge the leader of the previous generation. After winning against him, Rou officially became the new leader of the community. He then made things as comfortable as possible for the 5 women, as he continued to lead and train the community.
After torturing and killing the older goblins and one of the senior Hobgoblins, who attempted to defy his rules and assault the women, Rou gained the unquestionable fear and loyalty of the goblins, as well as the appreciation and trust of the women. With the community growing too big, Rou decided to move them to a mine, which he got by defeating Orcs. Since the goblins started to specialize in certain fields, Rou started to create separate divisions based on their abilities. After growing stronger, Rou pitted his strength against the forest's strongest Monster, the Red Bear. Despite losing his arm in the battle, upon defeating it, Rou ranked up to an Ogre, what more a Rare Variant. As the community grew stronger, with more goblins ranking up, they were soon asked by a desperate Carbuncle, Returner, to drive out or kill some humans which were invading its deceased master's dungeon. In return they could have its treasures. Having, fulfilled its request, Rou took the treasure, which included a magic silver arm to replace the one he lost.
Rou goes out to test his skills, defeating and absorbing the abilities of various Monsters, as well as having a passionate encounter with the Dryad, Doriane Duboué. Later the women that Rou saved and Gobumi decides to show their affection as well, having fallen for the black Ogre. The Goblin Community is then approached by an arrogant Elf noble and his subordinates, who wish to make the Goblins his subordinates for an upcoming war against the Humans. Rou refused the elf and scared him away, but the noble, seeking revenge came back with a retinue of skilled warriors. However, Rou managed to easily capture them and after killing a few (including the elf noble), kept the rest to use for breeding. Later, Gobukichi ranked up to an Ogre subspecies.
One of the senior generation Hobgoblins, Hobusei had Ranked Up to a Half Spell Lord. Later, Rou witnessed a kidnapping of an Elven girl in the forest. The girl happened to be the Elven Council leaders daughter, and was captured to use as leverage in the upcoming war between the Human and the Elves. Rou kills the kidnappers and returns the girl to her father, who was extremely grateful to Rou, both for saving his daughter, as well for the information the Ogre got from the kidnappers before killing them. Having established friendly relations with the Elves, Ogarou decides that he and his community will fight on their side in the upcoming war. Later, having obtained the [Monster Tamer] job from eating the kidnappers, the community starts capturing various wild Monsters, which Ogarou turned into familiars that he spread amongst the higher ranking members, though he kept a Hind Bear and a Black Wolf Leader for himself. On Day 59, Rubellia Walline (one of the five women) also gained a new job, becoming a Noir Soldier. The following day, several Kobolds fled to the Goblins caves, seeking refuge from a virtually endless assault of Skeletons. Rou decided to use this as an opportunity to level up the community and had everyone fight back. After finishing of the Greater Skeleton which was producing all the lesser ones, he checked on the Kobolds, who had chosen to swear their loyalty to him. Rou decided to accept them, having enslaved the Kobolds to ensure that they don't betray him.