Haruna is the central antagonist of the Tenchi Forever! film, a figure whose tragic past drives her to desperate actions. Her background is rooted in a forbidden love on the planet Jurai, where she was the lover of Yosho, Tenchi's grandfather. Because Haruna was not of royal blood, the two could not marry on their homeworld, leading them to flee to Earth with the hope of building a life together. The journey was arduous, and Haruna fell gravely ill, ultimately passing away just as their ship arrived on Earth. Yosho buried her body on the grounds that would later become the Masaki Shrine, where a camellia tree was planted at her grave. Over time, Yosho found new happiness, marrying a human woman named Itsuki and raising a family, including his grandson, Tenchi.

Haruna's personality is defined by a deep, unresolved sorrow that curdles into possessive longing. After death, her spirit became disturbed by the life Yosho built without her, feeling betrayed that he found happiness with another woman. This loneliness and sense of abandonment are the core of her motivations. Unable to accept her loss, she creates an elaborate, alternate dimension from her resting place within the camellia tree, a false world designed to recapture the love she was denied. Her primary motivation is to fill the emotional void left by Yosho, leading her to kidnap Tenchi, Yosho's grandson, as a substitute for the lover she lost.

Within this constructed reality, Haruna's role is that of a tragic captor. She ensnares Tenchi, erasing his memories of his family and friends and replacing them with a fabricated life where the two of them are lovers living together in an idyllic, turn-of-the-century Japanese town. Here, she manipulates his perception, causing him to believe his real life was merely a recurring dream. Her role in the story is to create the central conflict, forcing Tenchi's loved ones, particularly Ryoko and Ayeka, to fight not with physical force, but with emotional resolve to break her hold on him and restore his true identity. Haruna is depicted as a sympathetic figure rather than a purely evil antagonist; her actions stem from profound loneliness and a misguided belief that her created world is a rightful replacement for the real one.

The key relationship in Haruna's existence is with Yosho, the man she once loved. Her entire motivation is a reaction to his life after her death. Her relationship with Tenchi is a parasitic one; she needs his life force, his Jurai power, to sustain her artificial world, and she desires his affection to fill her own emptiness. The central conflict is resolved when Yosho directly confronts her spirit, slashing the camellia tree that anchors her existence. This act forces Haruna to recognize her own wrongdoing and to finally accept that Tenchi is not Yosho. In a moment of poignant resolution, she acknowledges the error of taking Tenchi away and lets him go, leaving her created world to collapse as she finally reunites with Yosho in the past.

Over the course of the film, Haruna undergoes significant development, transitioning from a desperate, manipulative spirit to a figure who accepts her loss and allows peace to return. Initially, she is driven by denial and possessiveness, but a confrontation with the real Yosho's essence forces her to confront the truth of her situation. Her development is a tragic arc where she must let go of the fantasy she has clung to for centuries. Her most notable ability is the creation and control of a detailed alternate dimension, a world she can shape to her will. Within this space, she has the power to manipulate memories, erase identities, and even banish intruders with a mere gesture. She also demonstrates the ability to drain the life energy from Tenchi to sustain her reality, making her a formidable, if non-physical, threat.