At the beginning of the Taisho Era there was a man in Tokyo running his private detective agency, and Mikagura Tokita was his name. Three young girls attracted by his genius joined him to help with his job. Will there be any culprit who would surpass their united wits?

Two years have passed since Tokito's sudden disappearance, and his private detective agency is now dismissed. One day a letter arrives to Shigeno from her older brother. There are rumors that Mikagura Tokito was seen in the city of Dalian. Now, all the girls set out in search of him across the sea, leaving dissatisfied Ranmaru in Tokyo. Will they discover Tokito? And what secrets this land is hiding?