Yuki, the hero who once saved another world, finally returns to Japan after defeating the Demon King. However, upon his return, mysterious dungeons begin appearing across nations worldwide. Inside these dungeons lurk monsters, along with vast treasures and rare items waiting to be claimed. At the same time the dungeons emerge, unique skills awaken within people on Earth—those who possess them are known as Hunters. Yuki takes the Hunter qualification exam and, despite his heroic accomplishments in another world, is registered as the lowest-ranked Hunter with the skill “Carrier.” Using the enormous number of items he brought back from the other world, Yuki sets out to conquer the newly emerged dungeons!