That Time I Got Reincarnated as a Slime

Mikami Satoru, a businessman murdered on the street, awakens in another world reincarnated as a slime. While exploring and consuming various resources, he discovers and befriends Veldora, a Storm Dragon sealed away for three centuries by a hero's powerful ability.

The slime Mikami is named "Rimuru" by the Storm Dragon Veldora, and together they adopt the family name "Tempest." Rimuru uses his Predator ability to absorb Veldora in an attempt to break the "Unlimited Imprisonment" seal, an act that causes a ripple effect across the surrounding nations. Unaware of the potential political consequences of Veldora's disappearance, Rimuru leaves his cave and encounters a group of Goblins.

Rimuru comes across a village of Goblins being attacked by a clan of Direwolves and decides to assist them in the battle. Later that night, the Direwolves return with the intent of taking control of the Great Forest of Jura.

Rimuru and his allies travel to the Dwarven Kingdom of Dwargon to seek artisans who can assist the Goblins in becoming self-sufficient. They are imprisoned after a conflict near the city gate, but their situation shifts when an Armorsaurus is reported in the surrounding mines.

Rimuru helps Kaijin complete a sword order for the king, and they celebrate at a bar with elf staff. During a fortune-telling session, an elf sees a vision of Rimuru's future partner, sparking curiosity among the group. Vesta arrives and begins teasing Rimuru, adding to the tension.

While working on improving the Goblin Village with Kaijin and the dwarves, Rimuru encounters a group of adventurers from the Guild, including a mysterious masked woman named Shizu. She is revealed to be the person destined for him according to his fortune, and like Rimuru, she is from Japan, though she was summoned to this world much earlier. Rimuru uses his Thought Communication ability to show her what Japan has become.

During the air raids on Tokyo, Demon Lord Leon Cromwell pulls Shizu out of the city and compels the powerful spirit Ifrit to take possession of her. Once inside her body, Ifrit goes on a destructive rampage.

Shizu, who was once captured by Demon Lord Leon, was rescued by a Hero, an event that inspired her to dedicate her life to helping others, including teaching children from other worlds. As her life nears its end, she asks Rimuru for a final favor.

Rimuru and the goblins' village continue to thrive, with the Dwarves constructing homes and furniture, and Rigurd being named Goblin King by the local lords. While Rimuru returns to his cave to practice techniques taught by Shizu, he is summoned back by Ranga via thought communication to assist against six Ogres in the Great Forest of Jura, one of whom demands to know his true identity.

Six Ogres survive an attack by an Orc army led by a mysterious warrior in plate mail and a clown mask, and they accept Rimuru's offer to join his forces, provided they can confront the Orc leader. Rimuru names each of them, while the Orcs begin invading the marshlands near Lake Siss, prompting the Lizardman chieftain to assign his son, Gabiru, a crucial mission.

Rimuru's village welcomes Benimaru and the five Ogres as new allies. Shortly after, the Lizardman Gabiru arrives, seeking support for a campaign against the Orc army. He challenges Ranga, who offers to listen if Gabiru can defeat Gobta.

The Orc army, under the command of the Orc Lord, advances through the Great Forest of Jura, prompting Treyni of the Dryads, the forest's guardians, to intervene. Having observed Rimuru's growing influence in the region, Treyni seeks his help in stopping the Orc Lord's campaign.

Rimuru and his Goblin riders travel to the marshlands to solidify an alliance with the Lizardmen, rescuing a Lizardman attacked by Orcs along the way. The rescued Lizardman is identified as Gabiru's younger sister, who reveals that Gabiru rebelled and left to confront the Orc Lord without waiting for the alliance. She begs Rimuru to save Gabiru and her clan, while Gabiru himself faces the overwhelming might of the Orc army and their devastating ability, Starved.

Gelmud, a powerful majin, reveals his plan to transform the Orc Lord into the Orc Disaster, a Demon Lord, so he can rule the Forest of Jura. Learning of this manipulation, the Orc Lord begins to take steps to resist his transformation.

Post-war negotiations commence after the battle with the Orcs. Rimuru discloses that he made a pact with the Orc Disaster, Geld, to assume the sins of all the Orcs. The Ogres and Lizardmen react strongly upon hearing this revelation.

The Jura Tempest Federation, led by Rimuru, forms an alliance with the Dwargon Armed Nation, bringing a sense of peace. However, this calm is shattered when a powerful entity arrives in the form of Mord Milim, a formidable Dragonoid known as the "Destroyer," whose overwhelming strength quickly overwhelms Rimuru's allies.

Phobio, one of Demon Lord Carrion's Three Beastketeers, launches a raid on Rimuru's city but is swiftly countered by Milim's powerful magic. Rimuru and his allies confront Phobio to learn the reason behind the attack.

Phobio struggles with his growing anger toward Milim and is approached by Footman and Tear, members of the Moderate Harlequin Alliance, who offer him the chance to become a Demon Lord using the power of Charybdis as a means of revenge. At the same time, Youm is sent on a mission by the Jura Tempest Federation to be recognized as the hero who defeated the Orc Lord.

With its seal lifted, the calamity-class monster Charybdis, accompanied by its Medalodon subordinates, launches an assault on Rimuru's capital city. The Jura Tempest Federation unites its forces under Rimuru's command to repel the attack, with King Gazel sending 100 Pegasus Knights for support. Faced with Charybdis's abilities of Magic Jamming and Ultraspeed Regeneration, Rimuru deploys his newly acquired skill, Gluttony.

With the threat of Charybdis eliminated, Rimuru has a dream of Shizu teaching in the Kingdom of Ingrassia, reflecting her unresolved regrets. Determined to fulfill her wishes, Rimuru departs from the Jura Tempest Federation and travels to the kingdom's capital. His first objective is to meet Yuuki Kagurazaka, the Guild's Grandmaster and a former student of Shizu.

Rimuru takes on the role of a teacher for Shizu's class, but faces resistance from the students, many of whom were unwillingly summoned to this world and are struggling with their shortened lifespans. To build trust and assess their strengths, Rimuru suggests a series of mock battles, offering them an opportunity to express their frustrations and showcase their abilities.

Rimuru seeks a solution to prevent the impending deaths of the children from Freedom Academy by proposing that superior spirits inhabit them, as was done with Shizu. He leads the group to the Dwelling of Spirits in hopes of finding suitable spirits, but their journey is interrupted by a powerful Golem controlled by the fairy Ramiris.

Rimuru and the children descend to the deepest level of the Dwelling of Spirits to attempt the summoning of powerful entities from a pedestal of light. One by one, Gale, Alice, Kenya, Ryota, and Chloe perform the ritual, but Chloe's summoning results in an unexpected and powerful spiritual presence. This mysterious being draws the attention of Ramiris, who appears to recognize something significant about it.

Before Rimuru's reincarnation, Shizu, known as the Conqueror of Flames, arrives in the Kingdom of Filtwood in response to an urgent summons. Upon reaching the castle, she finds a large gathering of adventurers, who have been assembled to confront a powerful demon that has recently been revived. While the demon has already killed over ten elite adventurers, the true nature of the request proves to be more complex.