The ephemeral and vivid brilliance of three men and a woman run through Yokohama.

Set in a Kyoto geisha house during the post-WWII era, the young Omocha begins her rigorous apprenticeship within the traditional community of geiko and maiko. She must navigate complex internal rivalries and a strict social hierarchy while the house struggles to maintain its customs. As modern society shifts around them, the residents face the increasing pressure of Japan's changing cultural identity.

The criminal library, dubbed the “Red Museum”, is a police facility that stores the investigation materials and evidence of major crimes where the statute of limitations has run out. Its director Saeko Hiiro is impassive and not good at communicating with people. One day, Satoshi Terada of the Tokyo Metropolitan Police Department’s First Investigative Division is assigned to be Saeko’s subordinate. Although he is bewildered by Saeko’s dispassionate demeanor, Terada starts to organize the data which is the primary responsibility of the museum. He encounters a traffic accident on the way to collect evidence. A truck has hit someone. When Terada rushes over, the victim utters the mysterious words “25 years ago... murder swap” and breathes his last. Once Saeko hears this, she declares a reinvestigation.