[Serialized as Book/Web Comic] Okutama Private Dungeon ~The Other World Labyrinth That Encroached

Yamagishi Kyoji, a high school student helping with his family's convenience store in Okutama, suffers a serious injury one day due to the effects of "Erosion" inside the store. After being transported to a hospital where he is healed by magic, Kyoji is drawn to jump into the "Erosion's Mouth" and discovers a labyrinth beyond it. A dungeon that suddenly appears in the modern world. And from the Erosion's Mouth, magical essence "Mana" overflows, giving birth to magic users and a new profession called "Adventurer." Materials that drop from within the dungeon are utilized in modern science, creating new industries, and the world gradually comes to understand the "Adventurer" profession.