Yuni Irido, originally Ayai, first married Ryonari and took the name Keikouin. After divorcing Ryonari due to his workaholic neglect of family, she reverted to Ayai. She later married Mineaki Irido, adopting his surname. Estimated to be in her early forties, she is Yume Irido's biological mother and Mizuto Irido's stepmother. She raised Yume as a single mother before remarrying.

Yuni possesses a strikingly youthful appearance, her beauty frequently likened to her daughter Yume's. She works as an office worker and manages household duties, often present at home more than Mineaki. Her parenting balances attentive support for both Yume and Mizuto with mindful boundaries, prioritizing family well-being and actively nurturing household harmony.

Her name reflects certain traits: "Yuni" combines "reason/cause" (由) and "compassionate" (仁), while "Irido" incorporates "that one" (伊), "logic" (理), and "door" (戸).