江戸川乱歩の作家デビュー100年を記念した“知られざる江戸川乱歩誕生秘話”。制作は連続テレビ小説「カムカムエヴリバディ」(2021年、NHK総合ほか)制作チームが手掛ける。後の江戸川乱歩こと平井太郎(濱田岳)は、初老の名探偵・白井三郎(草刈正雄)とバディーを組み、20世紀初頭の帝都を舞台に探偵稼業へと乗り出す。
At the beginning of the 20th century in Tokyo, the streets are rough, and the people yearn for a hero to emerge. Hirai Taro—who would later become the famed mystery writer Edogawa Rampo—harbors an intense admiration for foreign mystery writers, yet he is still an unknown author who is barely making ends meet by undertaking low-paying jobs. Despite bringing his manuscripts to newspaper publishers, Taro is completely ignored, until he meets Shirai Saburo, an elderly master detective full of humor and melancholy. His strength in the face of adversity impresses Taro, and in turn, Saburo is intrigued by Taro's eccentric ideas and moved by his boundless passion. The two form a partnership and embark on a journey into the world of detective work.