This is the perfect god in dreams. Shen Xi, who lives in Hong Kong and is a master of the Department of Architectural Design of A University, accidentally broke into the territory of ancient trees with tangled roots. He unintentionally spied on the secret of Xiao Huo, and an uncontrollable exchange of letters and a shikigami contract began. Ye Zhiqiu lives in Shanghai and is a sophomore in high school affiliated with B University. The secret words in the tree cave that have never been shared with others are completely known to Ashu. All the stories started from that winter. Ashu and Xiaohuo, Shenxi and Ye Zhiqiu are inseparable from each other. Maybe it's me in this story, maybe it's you.