Hyakko is a manga, and then series of anime created by Haruaki Kato. The opening theme is"Barefaced Rock" (Suppin Rokku) by Mana Ogawa, and the ending theme is "Namida Namida Namida" by Aya Hirano.
Hyakko takes place in the large and prestigious school Kamizono, a fictional giant institution located in Kyushu, Japan. Ayumi Nonomura is admitted to the primary year of school and lost in his first day in the enormity of campus. There he meets Tatsuki Iidzuka, Torako Kageyama, and Suzume Saotome on his preliminary day (all three were also lost), and four are good friends. The story is about their daily lives with their classmates something strange.