The phrase combines two everyday Japanese expressions: 'chotto matte,' meaning wait a moment, and 'uso desho,' meaning that cannot be true or you must be joking. Paired together they form a compact disbelief reaction that travels easily outside Japan through anime clips, edits and reaction videos. The exact original source of this recording is not documented, so its life is mainly online, where creators reuse the line for shocking news, fake-outs, prank reveals and moments when a character or streamer simply cannot process what just happened on screen.