Disowned and broke, Juugo Yama transfers to a high school on Nanae Island and moves into the cheapest apartment he can find, one haunted by Nanana Ryuugajou, a ghost who died ten years earlier and still can't leave the room. Nanana was once a legendary adventurer on the island, and Juugo ends up drawn into the school's 'treasure hunt royale' for pieces of her old collection, teaming up with the campus adventure club to chase down artifacts everyone else wants too.