Fubuki Kai is a self-made ninja who initially sees Miko Mido as her rival, driven by ambition to prove herself the more deserving candidate for headmaster of the Miroku ninja clan. Her early actions stem from this fierce determination to demonstrate superior talent and worthiness compared to Miko. A pivotal duel loss to Miko, fought sexually, changes her path. Craving power equal to Miko's, Fubuki Kai is subsequently adopted by the Shikima, a demon race from a parallel dimension. This adoption triggers a physical and metaphysical transformation, turning her into a Shikima demon and granting the enhanced strength she sought.

Emerging from this metamorphosis, Fubuki Kai becomes Miko's ally, shifting from adversary to companion. Yet, their relationship remains complex; she occasionally irritates Miko by showcasing greater proficiency or power in certain situations, reflecting her enduring drive to match or surpass her former rival even as an ally. She holds a fondness for her new Shikima form, embracing her changed identity and abilities.

Fubuki Kai possesses yellow hair, blue eyes, and a human-appearing adult form despite being 16 years old. She balances her life as a ninja with being a high school student. Her affiliations transition from the Miroku ninja clan to the Shikima Kingdom following her adoption and integration into the demon realm.