Shizuru had average length blue hair in her youth, which grew longer she got older. Her appearance was also quite similar to her daughter.
Though much of Shizuru's personality is unknown, she was shown to be a very loving and supportive mother to Fumino and wife to Reiji.
She often looked at the stars with her daughter and taught her the names and meaning behind them, which sparked Fumino's goal to become an astronomer. It is later revealed through a video recording she left on her laptop that in her high school years, she was embarrassingly bad at math, similar to her daughter. Despite this, she was able to improve through her hard work. Interestingly, she considers herself "an ally of the incapables", similar to Nariyuki.
During her school years, Shizuru was laughably bad at mathematics despite her desire to become a mathematician. Although through her efforts, she was able to overcome this difficulty and her grades on the subject improved.
Sometime after graduating from high school and enrolling in a university, she met Reiji. During her college years, Shizuru was regarded as a genius in mathematics and this status eventually followed her up to when she and Reiji became mathematicians, winning her numerous accolades for her ability to solve many difficult math problems that even most would not be able to solve. At some point, she and Reiji fell in love with one another and got married, leading to the two to have a daughter that they named Fumino.
Shizuru then suffered from an illness that tragically resulted in her death when Fumino was only a child.
- Both she and Reiji studied mathematics in university.