Azusa Arai is a supporting character who appears in the Kyoto arc of the Rurouni Kenshin story, specifically within the events depicted in the film Rurouni Kenshin: Kyoto Inferno. She is the wife of the swordsmith Arai Seiku and the mother of their infant son, Iori. Azusa is also the daughter-in-law of the legendary swordsmith Arai Shakku, whose final creations are central to the narrative. The family runs a small cutlery shop on the outskirts of Kyoto, living a quiet life far removed from the violence of the era.

In terms of personality, Azusa is portrayed as a kind and deeply caring woman, with her maternal instincts forming the core of her character. Her primary motivation is the safety and well-being of her young son, Iori. This love for her child is the driving force behind her actions during the film's most critical moments. While she respects her husband's wishes, she also demonstrates a practical and less idealistic view than Seiku, believing that a sword meant to protect could be a force for good rather than just an object stained by blood.

Azusa's role in the story is triggered by the arrival of the villainous Sawagejo Cho, a member of the Juppongatana known as the Sword Hunter. Cho comes to the Arai home demanding the location of Shakku's final and most powerful sword. When Seiku refuses to cooperate, Cho takes the baby Iori hostage to force their compliance. Driven by desperation and a mother's fear, Azusa reveals that the sword is kept as a holy relic at the Hakusan Shrine. This act sets the stage for the film's climax at the shrine, where Himura Kenshin battles Cho to save Iori.

Her key relationships are exclusively familial. Her bond with her husband, Seiku, is one of mutual respect, though she gently challenges his resolve to keep his father's legacy free from violence. However, her most significant relationship is with her son, Iori. It is her willingness to do anything to save him that reveals the sword's location. Later, when Kenshin is struggling against Cho, Azusa, alongside her husband, makes the crucial decision to entrust the legendary Sakabato Shinuchi to Kenshin. Trusting that he will use the sword to protect the innocent, she explains that this improved reverse-blade sword is the very reason her husband was able to agree to help, as it is a tool that cannot kill.

Azusa does not undergo significant character development, as her role is brief but impactful. Her defining traits of kindness and maternal courage are constants that drive the plot forward. She has no notable combat abilities or special skills; her strengths are entirely emotional and moral, rooted in her love for her family and her trust in Kenshin's cause. She is presented as a traditional stay-at-home wife and mother whose power lies in her protective instincts rather than any physical prowess.