Hayato's adopted older sister, who was raised with him by her grandfather. When she is with Hayato, she is bright and loving (as well as being clingy). However, when he isn't around, she is all business, acting professional and cold to most. She is a master of youjutsu (the art of using spellcraft directly in combat and enhancing the body) who wields a katana in battle. She became an orphan during the incident that wiped out the main family of the Isurugi clan. Her father, whom she had never met, was killed in battle, and due to an art her mother had placed that linked her own fate to her lover, she died at the same moment, leaving her an orphan. Seeing that her mother valued her lover more than her daughter, she came to despise the exclusive nature of her love, and when she began to display similar traits around Hayato, this emotion only became stronger. She is this story's semi-yandere.