In the distant future, humankind lives shoulder-to-shoulder in a cramped "Colony" divided by bedrock. Outside the colony extends a dangerous undeveloped area known as "The Labyrinth." Those who risk their lives to explore the Labyrinth and mark undeveloped areas are known as "Markers." Memempu is a young girl who wants to become a Marker, and Gagumber is a man who quit being a Marker. This rag-tag father and daughter team are about to take on the Labyrinth! "If there is no path, then dig one!