Inspired by such characters as Sherlock Holmes and C. Auguste Dupin, Kogoro Akechi first appeared in the "D Slope Murder Case" in 1925 and became the first recurring Japanese Detective character, appearing in stories for the next quarter century.
Like his inspiration, Sherlock Holmes, Akechi works as a consultant with the police, is an expert in Judo, and is a master of disguise. Though unlike Holmes, Akechi isn't above the concept of love, and has a wife (Fumiyo). About halfway through his history, he becomes involved with a group of youths (dubbed "The Boy Detective Club") whose leader (Yoshio Kobayashi) becomes his adopted son (and in some ways, his "Watson").
Akechi's most infamous foe is the "Fiend With Twenty Faces", a master thief who's gift with disguises outclasses even Akechi. The Fiend (occasionally called "K-20" at times in popular culture) is fueled by a desire to demonstrate/prove his brilliance than any actual desire for wealth. His true identity is shrouded in mystery.
Another memorable foe was the "Black Lizard", a brilliant female criminal mastermind who enjoyed not only collecting valuables and priceless items, but also human beings. Their battle of wits led to some shared affection between the two at one point.
-Black Lizard (1968): Live-action adaptation of Rampo's popular "Black Lizard" story, pitting Akechi against the notorious Black Lizard.
-Mystery of Rampo (1994): A semi-biopic about Edogawa Rampo having to deal with censorship from the government, as well as a bizarre murder mystery that plagues him, as it mirrors the murder implemented by a story he's yet to finish. Yet it soon transitions to a story about Akechi investigating the matter.
-Akechi Kogoro vs. The Fiend With Twenty Faces (2002): Made for TV movie cobbled together from various Akechi stories that pits the two against each other. Stars the popular Beat Takeshi as the Fiend.
-K20: The Fiend With Twenty Faces (2008): A movie set in an alternate reality where World War 2 never happened, and the dastardly criminal mastermind, K-20, the "Fiend With Twenty Face", is terrorizing Japan. The only person (seemingly) standing in his way is the courageous Kogoro Akechi, aided by an unjustly implicated/framed acrobat victimized by K-20. But things aren't always what they seem.