Detective Conan Episode - 7

: This is the first time Ran begins to suspect Conan is actually Shinichi .

💡 : Fans often discuss this episode because of Conan's noticeably "chubbier" animation style, which was unique to the early production designs. Detective Conan Episode 7

to stop the culprit in this episode, demonstrating their utility for the first time in a life-or-death situation. : This is the first time Ran begins

Beyond the specific case, this episode is a major milestone for the series' main plot: Detective Conan Episode 7

Depending on what you are looking for, "useful piece" might also refer to:

In this episode, the surgeon Masayuki Ogawa is being sent used toys and money every month. The most "useful" piece of evidence is .

: Conan notices a saved game file under the name "Ogino Tomoya" .