Gakkou no Kowai Uwasa Shin: Hanako-san ga Kita!!

Synopsis

The story of the anime revolves around Hanako, a girl who lives in a supernatural world apart from our own. Hanako appears when schoolchildren are in trouble; she is a benevolent version of an enduring Japanese urban legend about Hanako, a ghost who lives in a toilet at the local school. (Source: ANN)