Set on the fictional Mediterranean island of Callista on the eve of the outbreak of the French Revolution, the play depicts the struggles of a young officer who is torn between love, friendship, and his love for his homeland.

Harvey Rockwood, a world-renowned botanist, comes across bad weather and finds himself enveloped by a dense fog. Under the blanket of the mist, he hears the sound of the wind, the calls of wild birds, and then a mysterious singing voice in a garden where he meets Elu, the Spirit of the Blue Rose. Elu informs Harvey that they shall meet once again in the mist...

Nitta Kousuke, a police inspector in the Tokyo Metropolitan Police Force, is on the trail of a serial killer who leaves clues to the location of his next crime on his victims. Nitta uses the clues to discover that the Hotel Cortesia will be the site of the next killing, and goes undercover as a front desk clerk to help him unmask the killer. Yamagishi Naomi is the front desk clerk in charge of training him, and the two butt heads at every instance. Will they be able to unmask the killer before he strikes again?