Hyakko (ヒャッコ) is a manga created by Haruaki Katō. It started serialization on Flex Comix's free web comic FlexComix Blood on January 16, 2007. An anime adaptation produced by Nippon Animation was first aired in October 2008 in Japan. An OVA was released on October 17, 2009.
On their first day of high school shy Ayumi Nonomura and taciturn Tatsuki Iizuka become lost on the immense campus of Kamizono Academy. An irresistible force of nature named Torako Kageyama accompanied by her best friend Suzume Saotome appears in front of them. Led, sometimes pushed, by Torako, the girls and their classmates work through problems of school, home and adolescence.