The story follows the comic book artist Kevin Yamagata as he draws the popular detective series "Billy Bat".

The story begins in 1949 and follows Japanese-American comic book artist Kevin Yamagata, who creates the popular talking animal detective series Billy Bat.

Longtime collaborators Naoki Urasawa and Takashi Nagasaki worked on story ideas for Billy Bat for four years.

"[2] The postwar Japan setting of Billy Bat was partly inspired by David Peace's 2007 book Tokyo Year Zero.

Believing that young Japanese people were ignorant about the period and that society had completely forgotten about it, Nagasaki and Urasawa wanted to focus on postwar Japan to show how the country rose after World War II.

"[3] The first two chapters of the manga are drawn as the fictional Billy Bat American comic seen within the series, including being printed in full color with brown edges to mimic aging paper.

Although they received negative reactions from readers on the internet, Urasawa believed that plenty others suspected it was a "gimmick" and that he would not continue it in that style.

[30] Cristoph Mark of Daily Yomiuri called the first two Dick Tracy-like chapters, which are drawn as the fictional Billy Bat comic seen in the series, "a refreshing change of pace" but noted how they were received negatively by fans on the internet.

Anime News Network also noted how actions by characters in the story mirror the "ridiculous, creativity stifling" steps that The Walt Disney Company takes in regard to their own works.

[31] Mark Sammut of Comic Book Resources called Billy Bat a "fascinating manga that blends popular conspiracy theories and an engrossing mystery to craft a narrative that bends and twists seemingly every other page."