The slime Mikami and the Storm Dragon Veldora decide to give each other names. Veldora gives the slime Mikami the name "Rimuru," and Rimuru comes up with a family name for both of them: "Tempest." Then Rimuru uses his Predator skill to take Veldora into his body and analyze the "Unlimited Imprisonment" seal in hopes of breaking it... but this action sends a shock through the nations surrounding the Great Forest of Jura. With Veldora gone, there's a chance that the larger nations could become bold and invade the smaller provinces. With no knowledge of this, Rimuru leaves the cave and meets some Goblins.

After leaving the cave, Rimuru encounters a village of Goblins under attack by a clan of Direwolves. Caught in the heat of the moment, Rimuru agrees to help the Goblins in their battle. That night, the Direwolves arrive to try to take over as the new rulers of the Great Forest of Jura!

Rimuru and his companions visit the Dwarven Kingdom, the Armed Nation of Dwargon, in search of some artisans to help the Goblins learn to supply their own food, shelter, and clothing. However, a skirmish just outside the city gate lands Rimuru and Gobta in a prison cell. Then there's a report of an Armorsaurus in the nearby mines!

Thanks to Rimuru's skill, Kaijin was able to finish all the longswords and deliver them to the king, so the two of them celebrate by heading to a bar staffed by lots of elf girls. One of them reads Rimuru's fortune for fun, and sees an image in her crystal ball of someone she believes Rimuru is destined to be with. As everyone wonders who this person could be, Vesta shows up and starts to hassle Rimuru...

One day, in the midst of the improvements on the Goblin Village with the help of Kaijin and the dwarves, Rimuru meets a trio of adventurers from the Guild who've been temporarily joined by a masked woman named Shizu. Shizu turns out to be the person Rimuru is destined to be with, as his fortune said. Shizu also came to this world from Japan, but unlike him, she was summoned here many years ago. So Rimuru uses his Thought Communication skill to show Shizu what Japan looks like today.

The Demon Lord Leon Cromwell summoned Shizu out of Tokyo as it burned during in the air raids, then forced the high-ranked spirit Ifrit to possess her. After taking over Shizu's body, Ifrit begins to rampage.

When Shizu was still with Demon Lord Leon, it was a Hero who rescued her. That Hero was Shizu's inspiration to help as many people as she could for many years. She even worked as a teacher for children who'd come from other worlds. And now, as her time comes to an end, Shizu asks Rimuru for one last favor...

Rimuru and the Goblins' village is developing nicely. The Dwarves are building all kinds of houses and furniture, and the local Goblin Lords have appointed Rigurd as the Goblin King. As Rimuru watches everything come together, he decides to return to the cave and test the skills he received from Shizu. While there, he receives a request for help from Ranga through Thought Communication, and he rushes back to find his friends facing six Ogres. One of them orders Rimuru to "reveal his true identity." What is going on in the Great Forest of Jura?

Six Ogres are all that remain of their clan after an attack by an Orc army. They say that the Orcs were traveling with a mysterious majin who wore plate mail and a clown mask. Rimuru proposes that the Ogres join his ranks, and they accept on the condition that they will get to take down the one leading the Orcs, so Rimuru gives all six of them names. Meanwhile, the Orcs begin to invade the marshlands surrounding Lake Siss that are inhabited by the Lizardmen. So the Lizardman chieftan gives his son, Gabiru, an order...