Ten years ago, mysterious, laid-back characters called Danpons arrived from another world and created dungeons that have become a part of everyday life in Japan.
High school student Taira Ichino is invited by friends to explore the dungeon at Osaka Umeda Station. However, the place is teeming with people, making it impossible to defeat monsters properly. All he acquires are minimal experience points and a mysterious canned item called the “D-Can,” whose contents and method of opening remain unknown.
Back home, as Taira yearns for a personal dungeon, the D-Can suddenly opens. Inside, he discovers a candy that allows him to learn skills.
Taira learns skills from the candy and delves into dungeon, determined to become the strongest dungeon explorer…
