Arashi Kishyuu is one of the central characters in the story, serving as a member of the Dragons of Heaven, also known as the Seven Seals. She is a sixteen-year-old high school student who has been raised as a shrine maiden at the Ise Shrine, one of the most sacred sites in Japan. Known as the hidden shrine maiden, it is said that the great power of Ise is concealed within her body. Her name means storm or hurricane, which contrasts with her typically calm and reserved demeanor.

Arashi's background is marked by profound loss and hardship. Her mother was also a priestess at the Ise Shrine. When she became pregnant, she learned that her unborn daughter was destined to become a Dragon of Heaven. Hoping to spare Arashi from this fate, she fled the shrine. Following her mother's death when Arashi was seven years old, the young girl found herself living on the streets and surviving on garbage. She became so despondent that she considered letting herself die of starvation, as she saw no reason to continue living. It was at this time that she was found by Kaede, the high priestess of the Ise Shrine. Kaede took her in and convinced the despondent child to live, telling her that she would one day meet people who would care for her and that she herself would be sad if Arashi were to die. From that point on, a deep, mother-daughter-like bond formed between them, and Arashi was raised within the shrine to fulfill her destiny.

In terms of personality, Arashi presents herself as a strikingly beautiful but very cold, stoic, and serious young woman. She rarely loses her composure and can appear distant or irritated, finding it difficult to socialize with others. Her tragic past has forged a tragic and reserved character, but beneath this icy exterior lies a genuine capacity for kindness and concern, which she shows on rare occasions. As the story progresses, her cold demeanor gradually softens, particularly through her interactions with others who care for her.

Arashi's primary motivation is to fulfill her duty as one of the Seven Seals, protecting the world from the Dragons of Earth who seek to destroy humanity. She is one of the first to recognize the return of the central character, Kamui Shiro, and is dispatched by the dreaming clairvoyant, Hinoto, to observe and protect him, as he is the only one who can change the world's destiny. Her role in the story is as a dedicated defender, often fighting alongside her fellow seals to protect key locations in Tokyo and to prevent the end of the world.

The most significant relationship in Arashi's life is with fellow Dragon of Heaven, Sorata Arisugawa. From the moment he sees her, Sorata declares that she is the woman for whom he is destined to give his life, a prophecy he received as a child. Initially, Arashi is annoyed by his constant and open flirtations, treating him with marked coolness. However, over time, she shows signs that his attention troubles her, and she begins to develop genuine feelings for him, eventually falling in love. This relationship is central to her character arc. Her other key relationships include her guardian, Kaede, and her fellow seals, such as the young Yuzuriha Nekoi, with whom she develops a friendship.

Arashi undergoes significant development, driven largely by her love for Sorata. Her journey is one of moving from a state of emotional numbness and acceptance of a tragic fate to finding a reason to live and love. In the manga, after she and Sorata confess their feelings and consummate their relationship, she loses her power to summon her sacred sword, as a shrine maiden's power is tied to her virginity. Following this, she is trapped in a dream world by the corrupted Hinoto, who intends to turn her into a Dragon of Earth. In the anime television series, her love for Sorata leads her to make a desperate choice. To prevent him from dying to protect her as the prophecy foretells, she allows herself to be convinced to join the Dragons of Earth and attempts to kill Kamui, hoping to break her connection to Sorata. This path ultimately leads to tragedy, as Sorata dies protecting her anyway. At the end of the television series, she is last seen visiting Sorata's childhood home, where she finally allows herself to smile. In the feature film, her story ends in tragedy as well, as she is killed by Fuma shortly after witnessing Sorata's death.

Arashi possesses several notable abilities as a Dragon of Heaven. Her most prominent power is the ability to summon a massive and incredibly powerful sacred sword that emerges from her left hand. This sword is considered the greatest treasure of the Ise Shrine, with Arashi herself serving as its scabbard. She also has the power to detect shikigami, which are spirits or magical constructs given human form. Like all the Seven Seals, Arashi can create a barrier field, or kekkai, to isolate an area for battle. Her barrier is unique and takes the shape of a pyramid. In the manga, it is established that these abilities are contingent on her purity, and she loses the power to summon her sword after losing her virginity.