Hai linked me to an awesome set of editorials about teaching English in Japan, from a guy in the JET program. An excerpt:
Mousey tried to kancho me today. This was kind of surprising, as I hadn’t had any attempts in a while.
Y’see, kancho is mostly an elementary school thing. I’m grateful to say, kids grow out of the “Hey! Wouldn’t it be fun to stick my fingers up someone’s butt?” phase somewhere around 12-13 years old. So it’s rare to get any kancho attempts from the ninensei or sannensei. The ichinensei on the other hand…while they’re not particularly prone to it, they might bust it out for special occasions (like “welcoming” the new foreign teacher). April is particularly dangerous, because that’s when the ichinensei enter jr. high school straight from elementary school. New school, new asses, it’s like unlocking hidden levels in Ass Raider or something.
This is from an essay entitled “Ass Wars Episode VI – Return of the Kancho“, but believe me, there are many, many more. I wholeheartedly recommend them :D