The threat of Charybdis has gone. That night, Rimuru has a dream in which he sees Shizu teaching children at her school in the Kingdom of Ingrassia—a dream showing Shizu's lingering regret. To see her wishes through, Rimuru leaves the Jura Tempest Federation and heads for the capital of the Kingdom of Ingrassia. His first goal is to meet with the Grandmaster of the Guild, Yuuki Kagurazaka, who happens to be a Summon and a former student of Shizu's.

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 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? Amidst the uncertainty, the first to attempt the summoning is Gale, followed by Alice, Kenya, Ryota, and finally Chloe. But instead of a spirit, Chloe's summoning brings forth an unknown spiritual form with an immense amount of energy. Just what is this spiritual being? Ramiris seems to sense something about it...

A merchant from the east brings Hinata Sakaguchi a new book. In it she finds surprising information about the Jura Tempest Federation, a nation of monsters. As a former student of Shizu's, what goes through Hinata's mind upon learning about the existence of Rimuru? This special episode gives some hints as to what's coming in the new arc, as well as a look back at Rimuru's exploits thus far.

As prominent figures from several nations assemble in Tempest for a meeting, Laplace and his companions formulate a plan centered around Clayman. Then someone familiar joins the discussion...

Clayman and his pawns stand no chance against Rimuru and his allies. At a loss, Clayman orders Milim to use Stampede to kill everyone present, but Milim reveals he was never controlling her from the start. It was all an act to expose Clayman's plans and identify the mastermind behind it all. Even Carrion is still alive and well. On the brink of death, Clayman uses the souls of everyone he has killed as energy for his awakening. Thus the final battle to settle the score between Rimuru and Clayman begins.