Rimuru has returned to Jura after having attended Walpurgis. Diablo informs Rimuru of his mission to deal with the Kingdom of Falmuth. Having presented the kingdom with three options at a resolution, the clock on the week for their answer ticks down.

Yuuki is saddened by the death of Clayman, and Luminus is saddened by the death of Roy. Steeped in sadness, and having lost their friends, they seek their next move against Rimuru, who has grown in power and become a true Demon Lord.

Expecting visitors from all races to come calling after learning that Rimuru now controls the entire Great Forest of Jura, Rimuru decides to hold a festival to introduce himself and Tempest to the world, with the goal of attracting new citizens.

Responding to Rimuru's concerns about monsters in the forest harming humans, Vesta and Kaijin reveal a new invention they hope will keep the road to Tempest safe. Also, Rimuru assigns a new task to Geld.

A war council led by Hinata is held in the Holy Empire of Lubelius. Moments after Hinata declares her intent to meet Rimuru and talk to him, she receives a hostile message from Rimuru.

The spread of false information causes the Temple Knights to assemble, endangering Diablo's plan to conquer Falmuth. Meanwhile, Rimuru learns that Hinata is on her way to Tempest.

As Hinata makes her way to Tempest, the ramen and well-built roads she sees along the way prove to her that Rimuru genuinely wants monsters and humans to coexist. But against her wishes, one of her men is also on his way to Tempest...

The Crusaders have reached Tempest, and the battle is on. Hinata lays everything she learned from her mentor, Shizu, on the line in a life-or-death showdown against Rimuru.

Diablo descends before the enemy, King Edward of Falmuth. Also present are Saare and Glenda, two of the three Battlesages who are regarded as the most brilliant among the Master Rooks.