Place this clip right after the reveal shot and before your reaction cut, then follow it with the awkward moment sound effect for a longer pause or lead into the JoJo To Be Continued sting when the scene needs a cliffhanger ending.
About this sound
This is a short vocal clip of Conan making a drawn-out uu sound, lasting just under ten seconds. It feels puzzled and quietly suspicious, adding a tense, awkward beat rather than a loud punchline. The clip circulates from Detective Conan anime fandom, where that small reaction is used to flag that something does not add up.