Tokugawa Yoshimune rose to power as shogun after Ietsugu’s death, becoming the eighth ruler of the Tokugawa lineage. Born the third daughter of Mmitsuada, head of the Kii branch, she first governed as a domain lord before ascending to the shogunate. Her reign enforced strict austerity, dismissing courtiers from the Inner Chambers and instituting policies to stabilize the shogunate’s finances. She targeted administrative reforms in the Ōoku, challenging its tradition of sustaining large male retinues as symbols of authority. Scrutinizing bureaucratic practices, she contested the use of male names for women in official records, viewing them as hindrances to transparent governance. This led her to delve into archives like the *Chronicle of the Dying Day*, seeking the origins of these customs and their ties to societal upheaval triggered by the Redface Pox. To curb perceived excess, she streamlined Ōoku operations, appointing Kanō Hisamichi as Intermediator to restructure the administration. Pragmatic and unbound by tradition, she staged a mock execution to rescue groom-turned-consort Mizuno Yūnoshin from beheading after ceremonial defilement. Prone to impulsive romantic engagements both as domain lord and shogun, Yoshimune later relinquished power to her eldest daughter, Ieshige, yet retained considerable sway, often overshadowing her successor. This transition underscored the tension between her reformist ambitions and the shogunate’s entrenched traditions. Her study of the *Chronicle* uncovered Lady Kasuga’s historical manipulation—concealing Iemitsu’s death and establishing the matriarchal system. This discovery solidified her resolve to anchor governance in transparency and historical accuracy, despite opposition from conservative factions. Yoshimune’s rule blended rigorous reform with probing curiosity into the Redface Pox’s societal transformations. Her legacy endured through administrative innovations and her role in preserving the Ōoku’s evolving history.