Height: 160 cm (5'3")

Shioriko Mifune is one of thirteen members of the Nijigasaki High School Idol Club. She is a member of R3BIRTH, a unit under Nijigaku. She is a first year student and her image color is jade.

Shioriko is described as calm and academically gifted. She values Japanese tradition and has been trained in traditional dance and flower arranging. She has a talent for identifying people's strengths and weaknesses, and uses this to help students at Nijigasaki High School succeed in their club activities by offering advice. Although people are initially upset upon hearing her suggestions, they become thankful when it leads to them succeeding. And despite her somewhat stiff demeanor and lack of self-expression, Shioriko often yearns to connect with others, deep down.