Even as a young child, Haruka is calm and level-headed, often acting as a grounding force for her foster father, Kazuma Kiryu. Despite her age, Kiryu commonly leans on her for support with the other children at the orphanage. She is incredibly self-reliant and mature, seeking out work in order to help support her adoptive family, running errands on her own, cooking meals, and picking up the slack where Kiryu falls short. Her maturity extends to aspects of the nightlife, such as teasing Kiryu and Makoto Date by pretending to not know what a "soapland" is.