In of Detective Conan (titled "Once-A-Month Present Threat Case"), the "useful piece" likely refers to a specific clue or plot element that Conan uses to solve the mystery or progress the overarching narrative . 🧩 The "Key Piece" of the Case
Depending on what you are looking for, "useful piece" might also refer to: Detective Conan Episode 7
In this episode, the surgeon Masayuki Ogawa is being sent used toys and money every month. The most "useful" piece of evidence is . In of Detective Conan (titled "Once-A-Month Present Threat
to stop the culprit in this episode, demonstrating their utility for the first time in a life-or-death situation. to stop the culprit in this episode, demonstrating
: This is the first time Ran begins to suspect Conan is actually Shinichi .
: By checking hospital records, Conan discovers Tomoya was a patient who died three years ago on February 19th. This allows him to deduce that the sender is seeking revenge on the exact anniversary of the child's death. 🔍 A "Useful Piece" of Plot Development