After a brief stint as a teacher, the formidable slime Rimuru Tempest heads back to his kingdom, named after himself, just in time for crucial negotiations with the neighboring Kingdom of Eurazania. Despite the tense atmosphere, the talks conclude successfully, allowing Rimuru to resume his teaching duties. However, his plans to permanently return to Tempest are thwarted by a mysterious individual capable of suppressing his vast magical powers. Matters take a dire turn back in Tempest as unknown assailants launch a brutal attack on its populace, targeting both the elite and the common folk with lethal intent. Can Rimuru overcome this formidable adversary and safeguard his kingdom before it's too late?