Haruko Nakamori is the wife of Yousuke Nakamori and grandmother to protagonist Mai Kazuki. She co-leads the magical performance troupe Magic Carat with her husband, functioning as its organizational backbone and ensuring cohesion among members. Despite her age, she demonstrates notable energy and resolve, frequently intervening to manage situations when her more laid-back husband shows insufficient initiative. Her leadership extends beyond the troupe into family matters, where she provides steady support and stability.

Her responsibilities encompass coordinating Magic Carat's performances and managing logistical aspects of their shows. She appears in both the television series and the OVA "Semishigure," maintaining a consistent role throughout these appearances without significant development or expanded backstory.