When they find out their community is plagued by debt, three high schoolers in an old country town set out in search of some ancient buried treasure.

Naito Naito, a second-year high school student who has the ability to survive in any situation, teams up with Ryuo Soya, a talented boy whose father is the head of the Ryuo Group conglomerate. Along with others, they challenge "Area Z," a game created by a genius known only as "Kurii Eita." Can they complete their mission to save the city within 6 hours? An original story based on the characters of Hayamine Kaoru's mystery novels.