Myeong Ja is a former actress and Prism Star who once shared a romantic relationship with Kintaro Asechi, father of Kyoko Asechi and first husband of Kei. Despite her dedicated efforts, she grappled with meeting expectations in the Prism Show world during this period. Kintaro redirected his attention to cultivating Kei's abilities after witnessing her performances, fueling an obsession that eclipsed his interest in Myeong Ja. Distraught by this shift, she departed the relationship abruptly—though without formal closure—retaining a hollow Prism Stone designed by Kintaro, devoid of power or essence.

She later married an unnamed man, bearing two children. Yun-su, her eldest and only son, channeled childhood design pursuits into a professional career driven both by a desire to bring her joy and avenge Kintaro’s past cruelty. Myeong Ja deeply admires Yun-su’s design talents, their bond marked by mutual affection and respect.

Her second child and only daughter, Chae-kyoung, experienced childhood strain in their relationship. Chae-kyoung felt overshadowed by her mother’s acting legacy and pressured to replicate it, while perceiving Yun-su as more favored—particularly for his design endeavors—which bred resentment and a lingering sense of inadequacy in her own acting pursuits.

In later years, Myeong Ja’s aging became pronounced. Her presence in unfolding events surfaced mainly through flashbacks until Yun-su and his associate Shou sought her insights into the Symphonia series’ origins.