Nanana's Buried Treasure

Nanae Island, an artificial landmass in the Pacific, was built to provide young people with everything needed for education and training. Founded by the adventuring “Great Seven” led by Nanana Ryuugajou, it became a place where students can pursue their ambitions.

High schooler Juugo Yama arrives after being cut off and sent away by his family, relieved to escape his father’s control. Settling into his new room, he unexpectedly meets the ghost of Nanana herself, still tied to the island following her unresolved murder ten years earlier. Nanana reveals she concealed a set of strange, power-bearing objects around the island—the Nanana Collection—and Juugo joins forces with self-proclaimed “Master Detective” Tensai Ikkyuu and her cross-dressing maid Daruku Hoshino to track them down, hoping the hunt will lead to the truth behind Nanana’s death.