Age: 14 Birthday: July 10

Shion is Mion's identical twin sister, who currently resides in Okinomiya. In spite of their different personalities, she and Mion often switch places, and it can be difficult to distinguish between them.

She was sent by the Sonozaki family to a private boarding school, but escaped and returned to live near her hometown, where she lives with Kasai. In spite of all this, she and Mion maintain a close relationship. In most of the arcs, she is at a different school from the other main characters, and therefore appears less frequently.

She works as a waitress at the Angel-Mort restaurant and is the manager's assistant for the Hinamizawa Fighters little league team. She is often seen carrying a taser, and also wears yellow ribbon in her hair. She is also shown to be good with guns, along with Kasai, in Matsuribayashi-hen.