Saraka Tsukai represents the Japanese government as an international negotiator in talks with Yaha-kui zaShunina, the anisotropic entity. She presents as a 24-year-old woman with pale skin, dark purple hair layered with straight tips reaching her waist, and pinkish-red eyes. Her typical professional attire includes a black blazer, white blouse, and skirt. A ring on her right hand signifies a pledge of faith.

Her true nature is revealed as an anisotropic being, the administrator of humanity's universe, who has reincarnated throughout history and currently exists within a biological human family. While dedicated to her role, Saraka distrusts zaShunina's technological gifts—Kado, Wam, Sansa, and Nanomis-hein—viewing them as threats to human dignity and society's unprepared state.

Her interactions lead to a relationship with fellow negotiator Kōjirō Shindō, resulting in their marriage and daughter, Yukika Shindō. To prepare Yukika for a confrontation with zaShunina, Saraka and Shindō use Nanomis-hein to advance Yukika's relative age by 16 years. As a human-anisotropic hybrid, Yukika ultimately defeats zaShunina.

Within the *Beyond Information* movie continuity, Saraka's core role persists, though the narrative omits the Yukika storyline and leaves Shindō's fate ambiguous.

Saraka's personality merges professional resolve with personal vulnerability. Colleagues and family note her stubbornness, tendency for embarrassment, and tomboyish traits. She prioritizes universal stability over immediate benefits, emphasizing the universe's importance during negotiations. Recurring symbolic elements, like a childhood turtle motif, appear in her story.