Apparently, every toilet in every elementary school in Japan has a ghost. In the girls toilet is Hanako, and in the boys toilet is Taro.
If you spin around three times and say their name, you can invoke them. Then, when you sit on the toilet, the ghost reaches out of the drain and pulls your soul out of your arse.
Compromise and Conceit 
March 27, 2012 at 11:20 am
OMG for Hanako you’re either not lying or you’ve gone to the effort to setup a wikipedia page: http://en.wikipedia.org/wiki/Hanako-san
That also describes some variations on the legend.
I can’t find an easy English reference to Taro.