Chihaya Ayase has spent most of her life supporting her sister’s model career. When she meets a boy named Arata Wataya, he thinks Chihaya has potential to become a great karuta player. As Chihaya dreams of becoming Japan's best karuta player, she is soon separated from her karuta playing friends. Now in high school, Chihaya still plays karuta in the hope that she will one day meet her friends again.

Hyakko is a Japanese 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.