Mid-19th century, a world where various cities and nations exist. People live in their own ways, with individuals of diverse occupations and social statuses such as nobles, merchants, detectives, and phantom thieves active in society. Among them, Amoris is a city famous for its magnificent architecture, jewels, and valuables. A square clock tower stands at the center of the city, and to its east lies a large banquet hall, the largest building in the city. Large-scale banquets are held at the Amoris banquet hall, gathering invited guests from all over, and various jewels and valuables are exhibited at these events. In this particular banquet, a special gemstone called the 'Lucky Pendant' is scheduled to be displayed. You head to Amoris after receiving an invitation from the host of the banquet. From this moment, you become directly involved in the events surrounding the banquet and the Lucky Pendant.