Yui Shiraishi serves as a deputy chief, initially collaborating with Chisato Mizusawa. Born February 20 under Pisces in Gunma Prefecture, she stands 160 cm tall, weighs 48 kg, and has blood type B. Professionally, she exudes a commanding presence of confidence and resilience, concealing her struggle to express authentic emotions openly. Her relationship with Chisato intertwines rivalry with quiet admiration, creating a nuanced blend of competition and mutual respect.

Beyond work, Yui reveals a tender, whimsical side, particularly when lightly intoxicated. She willingly participates in social drinking—unlike some colleagues—but her low alcohol tolerance often leads to humorous scenarios where her husband, Masaki Shiraishi, must escort her home.

She has two younger sisters. Despite receiving a lucrative job offer promising a 50% salary increase, Yui prioritizes steadfast loyalty to her team, valuing their dependence on her over personal gain. Her choice underscores a commitment to camaraderie and the deep fulfillment she derives from her role.