Hiyori Jūjō is a 14-year-old third-year middle school student at Heijou Institute, hailing from Nara Prefecture. She wields the okatana Kogarasumaru and practices the Kashima Shinto-Ryu swordsmanship style, emphasizing speed and precision. Her appearance features long straight black hair, burgundy eyes, and fair skin; she is typically seen in her school uniform with black tights.

Her background is marked by significant loss. Her mother, Kagari Juujou, a Toji, died during the Great Disaster of Sagami Bay while failing to seal a powerful Aradama. Her father, related to the Hiiragi Family, was killed in action during his service in the Special Ritual Riot Squad when Hiyori was in elementary school. These events fueled her strong resentment toward Aradama and the Origami Family, whom she blamed for her mother's death, leading her to enroll at Heijou Institute to fulfill her mother's unfinished duty.

Hiyori exhibits a serious, stoic, and professional personality with a strong sense of responsibility. Determined to achieve her goals independently, she often conceals her emotions, leading to misunderstandings. Despite her reserved nature, she is skilled in household chores and cooking, abilities developed while caring for her ailing mother. She holds a particular liking for mint chocolate ice cream.

Her chronological story begins with participation in the National Swordsmanship Tournament in Kamakura City, where she dominated early matches but abandoned the final round to confront Yukari Origami, head of the Origami Family. This attempt failed, and she fled with Kanami Etou, who intervened to save her. Initially reluctant to accept help, Hiyori gradually formed alliances while in hiding. They encountered members of the anti-Origami group Mokusa, including Ellen Kohagura and Kaoru Mashiko, who later assisted them against the Origami Elite Guard.

Through Mokusa's leader, Akane Origami, Hiyori learned more about the Great Disaster of Sagami Bay, discovering her mother Kagari's pivotal role alongside Kanami's mother, Minato, in ending the catastrophe. This revelation strengthened her resolve, and she formally joined Mokusa alongside Kanami, Ellen, Kaoru, Mai Yanase, and Sayaka Itomi. During a festival celebration, Mokusa's headquarters was ambushed by the Special Ritual Riot Squad, forcing Hiyori and her allies to escape while several mentors were captured.

Following this setback, Hiyori demonstrated growth by relinquishing leadership to Mai and accepting the need for teamwork. Equipped with S-Equipment, the group launched a direct assault on the Origami Estate in Kamakura City. Hiyori defeated Maki Shidou of the Elite Guard and joined Kanami to confront Yukari, who had transformed into the Great Aradama Tagitsuhime. During the battle, Hiyori used her mother's sealing technique against Tagitsuhime, nearly sacrificing herself until Kanami rescued her from the netherworld.

Four months later, Hiyori returned to Nara and contemplated retiring as a Toji. However, after being informed by Heijou Institute's president, Iroha Gojou, about a hooded Toji attacking others during noro retrievals, she resumed her duties and reunited with Kanami in Kamakura City.

In the spin-off "Mini Toji," featuring chibi-style depictions, Hiyori retains her core personality traits within lighthearted, everyday scenarios. Her fondness for mint chocolate ice cream is highlighted as a recurring element; no new character development occurs in this non-canonical adaptation.