Nana Tanahata, a pharmacist, was tired of the days when she worked hard but didn't look good. She reunites with the university's senior and historical geek Takashi Kuwabara, who is also known as Tatar, and talks about . According to him, the Hyakunin Isshu has a hidden secret... On the other hand, an asset owner in Tokyo, a collector of Hyakunin Isshu, has been killed at home in Masakaki Dairoku. In his hand is a hundred Hyakunin Isshu card...! When the reunion with Tataru, the murder case, and the mystery of Hyakunin Isshu connect, the mystery of history that no one could know clearly emerges!!