Shinzaemon travels with the Natsugawa Genzaemon Troupe, an entertainment group visiting the cone-shaped land of Kikyōgahara in Shin Province. He serves as a companion alongside leader Genbanojō and member O-Natsu. Shinzaemon is a fox in human form, a secret exposed when Genbanojō transforms upon seeing the local girl Hana holding his favorite food, oyaki. Shinzaemon's existence as a shapeshifting fox is central to the story's revelations.

After their true nature is accidentally revealed to Hana, Genbanojō negotiates her silence in exchange for granting a wish. Shinzaemon's role is as one of the foxes whose concealed identity depends entirely on Hana keeping their secret. His actions and presence contribute to the collective identity of the fox group within the troupe. Shinzaemon's involvement is confined to the events of the troupe's visit and the fulfillment of Hana's wish for her great-grandmother to see cherry blossoms.