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!

Rimuru sends a delegation led by Benimaru to the Animal Kingdom of Eurazania, ruled by the Demon Lord Carrion, also known as the Beastmaster, to establish diplomatic relations after becoming indebted to him in the battle against Charybdis. A delegation from Eurazania is set to arrive in Tempest around the same time, but the Animal Kingdom is a very warlike nation, and Shion is enraged when one of the delegates, Suphia of the Three Beastketeers, makes a belittling remark toward Rimuru. The goal was a friendly relationship, but it takes no time at all for a fight to break out...

Despite the initial conflict, Eurazania and Tempest have deemed each other to be worthy of establishing friendly relations, and diplomacy between them officially begins. Tempest agrees to share its industrial techniques in return for Eurazania's agricultural techniques, and Rimuru decides to use the apple brandy produced as a result of this exchange to seek friendly relations with the Armed Nation of Dwargon next. He's accompanied by Shuna and Shion along with the former residents of Dwargon, Kaijin and the three Dwarf brothers, who are welcomed back to their home nation as state guests.

Tempest is preparing a feast in celebration of Rimuru's return home. Then a newcomer, the majin Myulan, arrives to scope out Tempest on the Demon Lord Clayman's orders, having joined up with Youm's crew as their military advisor in order to enter the nation. Upon arriving, she's surprised to see what a strong nation it is, but continues to talk with its citizens to learn more. Meanwhile, the king of Falmuth, who sees Tempest as a nuisance, conspires with the Western Holy Church in a plot to invade the monster nation.