Etrian Odyssey Untold: The Millennium Girl

This manga is based on the 3DS game of the same name. Highlander Lindis Fern's help is requested in the far away city of Etria, where an organization called the Radha hires him to explore the Yggdrasil Labyrinth and discover the cause of local earthquakes. Soon, the highlander discovers an amnesiac girl in a futuristic tube inside of a run down ruin, and meets fellow investigators from the Midgard Library.