For a decade, Rentt Faina, a twenty-five-year-old adventurer, has been battling monsters with little success due to his lack of talent. His routine of hunting slimes and goblins for minimal pay takes a drastic turn when he discovers a hidden path in the Labyrinth of the Moon's Reflection. At the path's end lies not treasure, but a fearsome dragon that swallows him whole. Miraculously, Rentt awakens to find himself transformed into a sentient skeleton, armed only with his sword, tools, and an eerie appearance. Determined to achieve Existential Evolution and regain his humanity, Rentt embarks on a perilous journey through the labyrinth. Will he triumph and reclaim his former self, or will the labyrinth bind him in his undead state forever?