Worldview: [Night of Flowers and Moon, the Shadow Sisters and the Five Blossoms]

1. Era and Setting The historical background is a fictional late Edo period, mid-19th century Japan, where Western culture is beginning to seep in. The main stage is 'Kagetsuro', a top-tier male courtesan house located in the heart of a massive pleasure district. This city of pleasure is filled with brilliant lanterns and the scent of incense at night; while it appears glamorous, it is a hub of desire where power, capital, and countless secrets intertwine. Kagetsuro is a closed and secretive place accessible only to high-ranking women, and its male courtesans are regarded as legends by the general public.

2. Atmosphere It carries the atmosphere of 'Romantic Fiction' where beauty and salvation coexist. On the surface, Japanese traditional aestheticism is maximized through scattering cherry blossoms, dances under the moonlight, and colorful kimonos. However, beneath lies the heavy reality of absolute status gaps, human lives swayed by money and power, and the inescapable shackles of the pleasure district. Players will experience fatal and desperate love, as well as power struggles, occurring within this magnificent birdcage.

3. Key Settings and Rules Kuro Family: An absolute conglomerate family that practically rules the economy and the underworld of all Japan. The two sisters of this family, 'Kuro Tsuki' and 'Kuro Hoshi', symbolize military and financial power respectively, possessing such immense authority that even the Shogunate walks on eggshells around them. The Five Flowers of Kagetsuro (Oiran): The five highest-ranking male courtesans representing Kagetsuro. Each bears the name and characteristics of a flower that symbolizes them. They are not merely selling their bodies but are cultured individuals proficient in art, literature, and etiquette. They were sold to the district for their own reasons and cannot leave Kagetsuro until their massive debts are repaid. Mizuage and Sponsors: To become a courtesan at Kagetsuro, one must undergo rigorous training, and to reach the highest rank, the support of a wealthy female sponsor (Danna) is essential. As the sisters of the Kuro family visit Kagetsuro, the fates of these five flowers begin to fluctuate wildly. Taboo: Guests must never touch a courtesan's body more than necessary unless the courtesan permits it.