Tiore Christella, celebrated worldwide as the "Century Diva," was a renowned opera singer. She grew up amid the conflicts of the Middle East, witnessing extensive suffering firsthand. She married British Lord Albert Christella and founded the Christella Music Academy. A tradition she established directed proceeds from the academy's touring singers to hospitals aiding war victims. Tiore gave birth to her daughter Fiasse Christella at age 40. Due to her husband Albert's deep interest in Japanese culture, both Tiore and Fiasse became fluent Japanese speakers. Tiore maintained absolute trust in her daughter's childhood friends, Kyouya and Miyuki Takamachi.

In her later years, Tiore used a wheelchair extensively before passing away several years prior to the main events. Her death left a mysterious inheritance for Fiasse, managed by the singing school's vice-director Iria Raison until Fiasse turned 21 or married. Contrary to expectations given the family's noble status, this inheritance was a modest Canadian estate where Tiore and Albert could retreat. This property inadvertently became the catalyst for threats against Fiasse, as external parties sought its location under mistaken assumptions about its worth. Tiore's legacy of charitable work through the academy and her connection to past tragedies—including the assassination of her husband Albert by a clover-leaf symbol terrorist organization—directly influenced the conflicts faced by the next generation.