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 tries to think of a way to save the children of Freedom Academy who are fated to die. The idea he comes up with is to have superior spirits inhabit each of them, as Shizu had, so their lives won't end prematurely. Determined to whatever it takes to save them, Rimuru leads the children to the Dwelling of Spirits, where superior spirits can be found. But as they make their way further inside, a Golem made of magisteel and controlled by the fairy Ramiris stands in their path.

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...

Rimuru, who is teaching Shizu's students as a substitute at the Kingdom of Ingrassia's Freedom Academy, takes part in an orientation in actual field combat in the school's annual outdoor training event. Transfixed by the prize he gets if he wins, he accepts a challenge by the teacher Jeff. However, an enemy appears before the students...

Rimuru, now a teacher at the Freedom Academy in the Kingdom of Ingrassia, has become involved in the school's outdoor training event with his class. The outdoor training event is an annual competition in which the students of each class guard the teachers on a journey to a nearby town. Rimuru is assigned to Class A, while his own students in Class S escort the young Tiss-sensei. All the students are eager to show how much their daily training has paid off, but the situation turns around when they're attacked by thieves!

Rimuru and the Class S students have made it through the first exercise of the Freedom Academy's annual outdoor training event. Class S has arrived first at the destination, the mansion of Count Guratol, and now they're ready to begin the second exercise, a cave exploration... but awaiting them there are thieves who hope to kidnap the students and make a fortune returning them for ransom money. Just when it seems like Rimuru's students have fought them off thanks to the skills he taught them, they realize a monster is lurking among the thieves! This is the final installment in the brand new episode created by the original author, Fuse-sensei, just for this OAD release!

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.

Римуру отправляет делегацию во главе с Бенимару в Звериное королевство Эвразании, которым правит Владыка Демонов Каррион, также известный как Зверолов, чтобы установить дипломатические отношения после того, как он стал его должником в битве против Харибды. Примерно в это же время в Темпест должна прибыть делегация из Евразании, но Царство зверей - очень воинственный народ, и Шион приходит в ярость, когда один из делегатов, Суфия из Трех звериных отрядов, делает уничижительное замечание в адрес Римуру. Целью было установление дружеских отношений, но не проходит и минуты, как вспыхивает драка...

В Темпесте готовится пир в честь возвращения Римуру домой. По приказу Повелителя демонов Клеймана в Темпест прибывает новоприбывшая маджин Мьюлан, которая присоединилась к команде Юма в качестве военного советника, чтобы попасть в страну. Прибыв на место, она с удивлением видит, какая это сильная страна, но продолжает беседовать с ее жителями, чтобы узнать больше. Тем временем король Фалмуст, который считает Темпест помехой, вступает в сговор с Западной Святой Церковью и замышляет вторжение в страну монстров.

Одновременно с нападением на Темпест, нападению подвергается и Римуру. Присмотревшись, Римуру понимает, что нападавший - один из бывших учеников Шизу, потусторонний человек, а затем женщина представляется сильнейшей из Святых Рыцарей, Хинатой Сакагути. Римуру оказывается загнанным в угол, когда ее Святое поле запечатывает большую часть его магии. В то же время Шион и Хакуру, чья магия была запечатана аналогичным барьером, оказываются зажаты в угол Сёго и Кёя.