This is a translation of a Japanese webnovel. When I regained consciousness, I found myself seated in a plain stone chair within the dark depths of a dungeon. Natsuo Miyama had somehow become the Dungeon Master, though the reason for this remained uncertain. The dungeon, which connected to a natural cave, was a harsh and unforgiving place where even a decent life was impossible to expect. To make matters worse, the methods required to thrive in this environment were abhorrent to modern Japanese sensibilities. I hesitantly began perusing the monster catalog, hoping to find a creature to aid me in my endeavors, but my efforts were quickly interrupted by an attack from enemy monsters. Summoning the right monsters and managing the associated summoning costs soon became the least of my worries. The challenges continued to mount as I sought to improve the dungeon, defeat enemy forces, and earn coins for summoning new monsters. The only solace in this unforgiving environment came from the receptionist at the monster delivery center and the kobolds who cared for me. My story is one of a young man struggling to become a successful Dungeon Master. As I strive to enhance my dungeon by defeating foes and summoning new creatures, I am faced with a myriad of obstacles and challenges along the way