Butt Detective, or Oshiri Tantei in Japanese, is a sleuth distinguished by a face mimicking human buttocks, featuring pronounced cheeks and a cleft. He sports a beret passed down from his father, Oshiri Dandy, paired with a meticulously styled side part that accentuates his refined persona. His investigations begin with the catchphrase “Hmm, I smell a case…” and conclude with “Pardon me while I ‘poot’ you in your place,” deploying flatulence to subdue foes—a tactic that occasionally backfires on his steadfast companion, Brown, a small brown dog.

Rooted in a family legacy of detective work, his father’s beret symbolizes inherited sleuthing prowess. His intellect, humorously denoted by an IQ of 1,104 (a phonetic play on “ii oshiri,” meaning “nice butt” in Japanese), underscores his sharp deductive skills intertwined with wordplay. A fondness for sweet potatoes adds whimsy, aligning with his digestive-themed antics.

His cases span books, TV episodes, and films, tackling art heists, forgeries, and covert schemes. A notable film plot pits him against an art-forgery syndicate, testing his ethics through a fraught alliance with Suisen, a former partner of ambiguous loyalty. Despite physical setbacks, his resolve to uncover truth overrides personal bonds, highlighting his unwavering pursuit of justice.

Brown serves as his loyal aide, while adversaries like Phantom Thief U—a cunning rival—and authority figures like Chief Maltese anchor him within a procedural framework. Stories blend toilet humor and visual jokes with earnest mystery-solving, inviting audience interaction through puzzles that echo the series’ educational origins in teaching Japanese language basics.

Licensed merchandise, from lunchboxes to bath bombs, prominently features his iconic buttocks motif, cementing his status as a children’s entertainment staple. Though spin-offs remain unconfirmed, his consistent portrayal across media reinforces a commitment to quirky crime-solving, merging absurdity with methodical deduction.