Saya Kisaragi is a cheerful, honest and kind girl, who trains as a shrine maiden under her father Tadayoshi Kisaragi, spending her days quietly with her schoolmates Itsuki Tomofusa, Yūka Amino and Nene & Nono Motoe. During her journey to school, Saya meets a small dog. However, those outside her family are oblivious to her secret life as a swordswoman dedicated to slaying monsters called Elder Bairns. That night, she faces and defeats a Jizo Elder Bairn.