Nanae Island is a constructed landmass in the Pacific Ocean that provides every facility required for children"s comprehensive learning and skill development. It was built by the Great Seven, a band of explorers led by Nanana Ryuugajou, to give youngsters a place where they could pursue their aspirations.
After being abandoned and expelled by his relatives, high‑schooler Juugo Yama reaches this isle, elated to finally escape his father"s shadow. When he settles into his new quarters, he encounters the specter of Nanana Ryuugajou, tethered to the island following her unresolved murder a decade earlier. Nanana reveals that before dying she concealed artifacts imbued with extraordinary powers throughout the island—these are known as the Nanana Collection. Determined to uncover evidence that will lead him to her killer, Juugo teams up with self‑styled "Master Detective" Tensai Ikkyuu and her cross‑dressing housekeeper Daruku Hoshino, embarking on the quest. Their investigation will uncover hidden secrets that reshape the island"s destiny.
A-1 Pictures Inc. Japan