Genyo rules the demon realm Makai with a focus on preventing the prophesied Chōjin from merging the human, demon, and man-beast worlds. To preserve her realm’s sovereignty, she enlists her champion Suikakujū to assassinate Amano Jyaku, a man-beast guardian shielding the Chōjin’s chosen vessel. Centuries of rivalry pit Genyo’s manipulative schemes against Amano’s confrontational tactics, both vying to control the Chōjin’s fate.

In the early 2000s, Genyo identifies Norikazu Ozaki as the Chōjin’s human host and commands Suikakujū to eliminate Amano, triggering a chain of events where Suikakujū assaults Genyo’s daughter Seigenki under the pretense of royal sanction—a calculated move to cement dominance. Simultaneously, Genyo infiltrates the human world via a corporate network, merging demonic strategy with mortal institutions to monitor threats and manipulate hierarchies.

Her reign prioritizes Makai’s survival above all, employing strategic ruthlessness, subterfuge, and familial exploitation to neutralize rivals and maintain authority. While her origins remain undisclosed, her legacy centers on opposing the Chōjin prophecy through orchestrated conflicts, leveraging subordinates to uphold her rule without ethical restraint.