Hinomoto Sada regularly sells yogurt around the Gifu Air Base, presenting as an elderly woman. This mundane role masks her quiet observation of the current Dragon Pilots. She is actually the last surviving D-Pilot from the Ritual seventy-four years prior, where she piloted Masotan under the callsign "Montparnasse". Her piloting experience ended tragically with the sacrificial death of her beloved childhood friend and girlfriend, Yae, the leading miko for their Ritual. Yae was offered to Mitatsu-sama, the colossal dragon guided to rest every seventy-four years, a sacrifice then deemed essential for the Ritual's safe completion and the dragon's peaceful slumber. Witnessing this event caused Sada to withdraw permanently from the OTF squad, leaving only Yae's clothing as a stark reminder of the cost. Following this trauma, Sada distanced herself from the OTF program yet maintained peripheral involvement, using her yogurt-selling routine to covertly monitor the new generation of pilots. Her deep knowledge of the dragons and the Ritual's true nature became critical when the current cycle began. She reemerged as a mentor, providing essential guidance on the Ritual's mechanics and history to Hisone Amakasu and the others. Her insights were vital in challenging the long-held belief that human sacrifice was unavoidable for the Ritual's success. Understanding dragon behavior and the emotional bond between pilot and OTF, she supported Hisone's unorthodox approach. Sada contributed significantly to developing the alternative "sleep-turning" technique for Mitatsu-sama during the Ritual, eliminating the need to sacrifice the current leading miko, Natsume Misumi. Her actions ensured the Ritual's completion without further loss of life, altering the tradition for future cycles. Afterward, she continued her life at the air base, her experiences leaving a lasting legacy on the OTF program.