After being taken into Rimuru's body, Ifrit awakens to find the Storm Dragon Veldora standing before him. Veldora calls Ifrit to where he is, delighted to find a new conversation partner. Thus the two of them begin to watch over Rimuru's actions from within him.

This story takes place before Rimuru's reincarnation. Shizu, also known as the Conqueror of Flames, responds to an urgent request calling her to the Kingdom of Filtwood.

Rimuru and the children reach the deepest level of the Dwelling of Spirits, where they stand on a pedestal bathed in light to summon superior spirits. Will their summoning be successful?

Rimuru, Ranga, and the students enter the Dwelling of Spirits and are immediately met by a giant metal golem. Rimuru easily defeats it and one of the ten Demon Lords introduces herself. Can this tiny spirit really be one of the ten Demon Lords?!

Rimuru becomes the new teacher for Shizu's students. However, having been summoned into this world against their will and facing shortened lifespans as a result, the children's feelings are complicated, and they're reluctant to accept Rimuru. So Rimuru proposes a series of mock battles with each of them to ascertain their abilities and allow them to let off steam.

Rimuru has a dream in which he sees Shizu teaching children at her school in the Kingdom of Ingrassia, showing Shizu's lingering regret. To see her wishes through, Rimuru leaves the Jura Tempest Federation and heads for the capital of Ingrassia.

Rimuru and his forces attempt to destroy Charybdis with a full on attack, but fail, so Rimuru decides to take on Charybdis alone and learns the shocking truth!

Phobio can't restrain his anger toward Milim. He finds himself faced with Footman and Tear, two masked members of the Moderate Harlequin Alliance, who suggest that he become a Demon Lord to take revenge on Milim.

The Demon Lord Carrion has sent one of his Three Beastketeers, Phobio, on a raid of Rimuru's city. However, Phobio is quickly defeated when Milim meets his attack with her own. Rimuru and his subordinates then ask Phobio why he has come to their town.

The Jura Tempest Federation, with Rimuru as its leader, has formed an alliance with the Armed Nation of Dwargon. Just as Rimuru thinks there are only peaceful days ahead, he senses an enormous mass of magical power heading straight for his location.

Post-war arrangements following the battle with the Orcs have begun. At the meeting, Rimuru reveals that he made a promise with the Orc Disaster, Geld, to take all of the Orcs' sins upon himself. When the Ogres and Lizardmen hear this...

The majin Gelmud makes his appearance at last. His true goal was to evolve the Orc Lord into the Orc Disaster, a Demon Lord, and have him reign over the Forest of Jura. Upon learning this, the Orc Lord takes action...

Rimuru and his Goblin riders set out for the marshlands to finalize their alliance with the Lizardmen. On the way, they save a Lizardman who'd been attacked by the Orcs.

The Orc army, led by the Orc Lord, continues its conquest throughout the Great Forest of Jura. The crisis has spurred Treyni of the Dryads, the caretakers of the forest, to take action. She has had her eye on Rimuru after noticing his rise to prominence in the forest, and she wants Rimuru to defeat the Orc Lord.

Rimuru's village has gained Benimaru and the other Ogres as its newest allies. Soon after, the Lizardman Gabiru visits the village. Gabiru has been visiting Goblin villages throughout the Great Forest of Jura to ask for aid in fighting off the Orc army.

Only six members of an Ogre clan remain after an attack by an Orc army led by a mysterious majin wearing plate mail and a clown mask. Rimuru asks the Ogres to join his ranks, and they accept on the condition that they will get to defeat the Orc's leader.

Rimuru and the Goblins' village is developing nicely. The Dwarves are building houses and furniture, and the local Goblin Lords have appointed Rigurd as the Goblin King. As Rimuru watches everything come together, he decides to test his new skills.

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...

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.

One day, while working on the improvements to the Goblin Village, Rimuru meets a trio of adventurers and a masked woman named Shizu. Shizu turns out to be the person Rimuru is destined to be with, according to his fortune.

Thanks to Rimuru's skill, Kaijin was able to make and deliver all of the longswords, so they celebrate by going to a bar staffed by elf girls. One of them reads Rimuru's fortune, and sees an image of someone she believes Rimuru is destined to be with.

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!

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!

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."

Mikami Satoru, a businessman, is stabbed by a criminal on the street and killed. When he regains consciousness in the darkness, he finds that he's been reincarnated as a slime!