Hanako-san -- a spooky young girl that haunts school restrooms across Japan -- has in recent decades become one of the nation's most famous ghosts.

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.

Toire no Hanako-san, by Digital Dolls

Details about Hanako-san's origins are murky. Although she became a national phenomenon in the 1980s, there is speculation that she has existed since the 1950s. Some stories claim she is the ghost of a WWII-era girl who died in a bombing raid on the school while she was playing hide-and-seek. Other stories claim she is the restless spirit of a young girl who met her end at the hands of an abusive or deranged parent (or a perverted stranger, according to some stories) who found her hiding in the bathroom. In some cases, she is the ghost of a former student who died in an unfortunate accident at the school (one story from Fukushima prefecture, for example, claims she is the ghost of a girl who fell out of the library window).

Hanako-san photo by Sammi Sparke

Countless versions of the Hanako-san legend have emerged over time. Here are a few of the more colorful variations:

- According to one Yamagata prefecture legend, something terrible will happen to you if Hanako-san speaks to you in a nasty voice. Another legend from Yamagata prefecture claims that Hanako-san is actually a 3-meter-long, 3-headed lizard that uses a little girl's voice to attract prey.

- At a school in the town of Kurosawajiri (Iwate prefecture), it is said that a large, white hand emerges from a hole in the floor of the third bathroom stall if you say "third Hanako-san" (sanbanme no Hanako-san).

- In the boys' room at a school in Yokohama (Kanagawa prefecture), it is said that a bloody hand emerges from the toilet (presumably an old-fashioned squatter) if you walk around it three times while calling Hanako-san's name.

- Stories have also circulated about a so-called "Hanako fungus" that can infect anyone who scrapes their knee on the playground. The infection reportedly causes tiny mushrooms to sprout from the scab.

Toire no Hanako-san, by HAL-2oo6

For the most part, Hanako-san is harmless and can be avoided simply by staying away from her designated hiding spot. But if you ever need to get rid of her, try showing her a graded exam with a perfect score. Some legends claim that the sight of good grades makes her vanish into thin air.

[Note: This is the latest in a series of weekly posts on Japanese urban legends.]