is a Japanese prank performed by clasping the hands together in the shape of an imaginary gun and attempting to poke an unsuspecting victim's anus, often while exclaiming "Kan-CHO!".
The word is a slang adoption of the Japanese word for . In accordance with widespread practice, the word is generally written in katakana when used in its slang sense, and in kanji when used of enemas in the medical sense.
It is a form of prank amongst children in East Asian countries such as Japan, Korea, and Taiwan, etc. In Korea, it is called ttongchim.(똥침) In Taiwan, it is called Qiānnián shā (千年殺).