Rimuru's nation, Tempest, is in a state of great excitement as the grand opening festival approaches. The festival begins with the unexpected arrival of Hinata, the powerful captain of the Holy Knights, who has agreed to take care of Rimuru's five children—Kenia, Alice, Ryota, Gale, and Chloe—in place of their bedridden teacher. Meanwhile, Rimuru prepares for diplomatic matters, including a visit from Lady Luminus, who proposes a cultural and technological exchange between their nations to further strengthen their alliance.

During the festival, numerous activities take place, including a concert that captivates both humans and monsters, breaking down social barriers. This is followed by a technological presentation by Vesta and Gabiru, who showcase groundbreaking research on the properties of the Magic Owl and its effects on plants and objects, fascinating and surprising the audience.

As the festival progresses, Rimuru faces a financial challenge when Mjöllmile reveals that Tempest is suffering from a shortage of usable currency due to sabotage by external forces aiming to undermine the nation's reputation. Rimuru and his advisors discuss various strategies to overcome the situation without jeopardizing their standing or relationships with other nations.

Amid these diplomatic tensions, Rimuru and Lady Luminus agree on a cultural exchange, which also includes the introduction of a new skill called the "Mystery of Faith and Grace," allowing Rimuru's followers to harness his power. The episode concludes with anticipation for the next major event: the Tempest Martial Arts Tournament.