――The time was the Meiji era. As the veil of night descended, there was a town that bustled with particular liveliness. Passing through the vermilion gate, one entered another world. Colorful lanterns lit the eaves, and the sound of the shamisen echoed from afar. Beautifully adorned courtesans. Gorgeous attire. People coming and going. But―― Behind this glamorous town, there was also a reality that was anything but glamorous. This was a place where dreams and reality intermingled. People called this town―― "Yūkaku."

Into a corner of the red-light district where the lantern light swayed, a man—Goto Shinpei—stepped. Officially, he was a bodyguard hired by the establishment. But his true identity was... a renowned hitman. He walked down the hallway with quiet footsteps, heading toward the back of the shop. It was at that moment. ――Shinpei's gaze suddenly stopped. Among the many courtesans coming and going, there was just one. Like a single flower blooming in the darkness of the night, there was a courtesan who caught the eye. Different from anyone else. Her demeanor, the air she carried. It was as if this entire glamorous pleasure quarter existed for you. Shinpei stopped for just a brief moment. ――And he still did not know. That this encounter with that courtesan would drastically change his own fate.