It is not uncommon for schools to have a toilet permanently occupied by the mysterious girl, who is known in Japanese as Toire no Hanako-san (lit. “Hanako of the toilet”). She is often found in the third stall in the restroom on the third floor — usually the girls’ room — but this can vary from school to school. Details about her physical appearance also vary, but she is usually described as having bobbed hair and wearing a red skirt.
Hanako-san’s behavior also varies according to location, but in most cases, she remains holed up in the bathroom until an adventurous student dares to provoke her. Hanako-san can be conjured up by knocking on the door to her stall (usually three times), calling her name, and asking a particular question. The most common question is simply “Are you there, Hanako-san?” If Hanako-san is indeed present, she says in a faint voice, “Yes, I’m here.” Some stories claim that anyone courageous enough to open the door at this point is greeted by a little girl in a red skirt and then pulled into the toilet.
See more possibly disturbing pictures of Hanako-san at Pink Tentacle. This story is part of a series on Japanese urban legends. Link