Fireball Oroku, also known as Oroku, Granny Oroku, or Oroku the Fireball, is a significant character residing in the Tama Hills region, the primary setting of the film. As an elder of the tanuki community, she holds a position of high respect and is often referred to as grandma by the other tanuki, a testament to her revered status as a matriarch and peacekeeper.

In terms of appearance, Oroku is most often seen as a grey-furred tanuki with neatly pinned black hair, wearing a traditional red kimono. When she chooses to take human form, her appearance is that of a middle-aged woman, closely resembling her tanuki guise. Her personality is defined by rationality, wisdom, and an exceptionally strong will. She is not prone to impulsive action but rather demonstrates a clear-headed understanding of the grave situation facing her people. This combination of strength and wisdom makes her a natural leader and a unifying figure among the various tanuki factions.

The central motivation for Fireball Oroku is the survival of the tanuki race in the face of encroaching human development. As the suburban expansion of Tokyo destroys their forest habitat and diminishes their food supply, the tanuki initially turn on each other, fighting over dwindling resources. Oroku is the pivotal figure who intervenes during this period of infighting, compelling the disparate and desperate tanuki to cease their internal conflict and unite against the common human enemy. Her role in the story is therefore that of a catalyst for action and a guiding force. She is instrumental in the formation of the resistance, working alongside other prominent leaders such as the aggressive chief Gonta, the old guru Seizaemon, and the resourceful young tanuki Shoukichi. While others may provide muscle or strategy, Oroku provides the moral authority and the initial spark needed to organize the resistance.

Her key relationships are largely defined by her matriarchal status. The entire tanuki community looks to her for guidance. She is not a warrior on the front lines, but rather a strategic and spiritual anchor. One of her most critical contributions is her role in re-teaching the younger generations the lost art of transformation, also known as illusion science. This ancient skill, which allows tanuki to shapeshift into virtually anything, becomes the primary weapon in their struggle against the humans. By leading this educational effort, she ensures that the resistance has the practical tools to conduct sabotage and scare away construction workers.

Throughout the narrative, Fireball Oroku remains a steadfast symbol of tradition and resilience. While some tanuki become enamored with living as humans or lose hope in the old ways, Oroku maintains her commitment to tanuki identity and the fight for their land. Her personal development does not follow a typical arc of transformation, as she begins as a wise elder and ends as one. However, her final act in the film is a poignant reflection of her enduring spirit. After the tanuki ultimately fail to stop the complete development of the hills, she does not disappear or surrender. Instead, she adapts, becoming a fortune teller. This new role allows her to continue interacting with the human world, now observing and commenting on its path from a different perspective, demonstrating her unyielding will to survive and adapt even in the face of defeat.

Fireball Oroku possesses several notable abilities. Foremost among these is her profound mastery of transformation, the fundamental magical ability of the tanuki. She is skilled enough not only to transform herself but also to instruct others in reclaiming this lost art. Her very nickname, Fireball, hints at a specific and potent transformation, possibly referring to a powerful, luminous form she can assume. Beyond her supernatural skills, her greatest abilities are her wisdom, her political acumen in uniting the warring tanuki, and her extraordinary force of will, which commands the respect and loyalty of her entire community.