Shiori is a frail-looking young woman who has a light complexion and blue eyes. She has short, straight brown hair that comes down to her neck. She usually wears a woolen white jumper underneath a brown checkered jacket. She wears her school socks which are black and knee-high, as well as black school shoes.
Shiori loves drama and is always inventing reasons for things that happen in her life, but the real-life drama of a sister who denies her and a life threatened by illness is encroaching on her. While she was sick her sister ignored her, so she stayed out of her way.
Sick as she is, Shiori thinks nothing of sitting outside the school for hours on end while eating ice cream in the middle of winter, despite Yuichi telling her several times to go home and rest.
Due to her illness, it is not strange for her to carry around an array of different pills and drugs for her many ailments. She has a noticeably quiet voice. Shiori informs Yuichi early on that the reason she disobeys her doctors' advice and comes to school so frequently is that she wants to meet someone she knows. She is the only heroine in Kanon whom Yuichi did not meet in the past.
One week Shiori went to school like a normal student and cooked a bento for Yuichi, while Sayuri was in the hospital, but it was a bit too much for him.