After a life filled with hardships, Ryouma Takebayashi passes away at 39, only to be granted a new beginning by three compassionate deities. Reborn in a magical realm, he is tasked with embracing his true self and finding joy in existence. Endowed with extraordinary physical prowess and mastery over all elements, Ryouma commences his rejuvenated life as a child in a lush forest. Immersing himself in slime research, he refines unique slime species and hones his magical prowess, forming a formidable army. Despite contentment in his isolated cavern abode, Ryouma yearns for human companionship. A chance encounter with wounded travelers leads him to leave his sanctuary, venturing into a world where his magical talents and slime expertise astonish all he meets.