Halle is one of the five central high school students in this anime film. She generally possesses a calm and composed personality, but beneath this quiet exterior lies a strong determination and a deep-seated desire to achieve her dreams. Her primary background and personal interest lie in the academic pursuit of religious studies, which she is so passionate about that she is already studying at a graduate school level to further her research in this field.

Her central motivation throughout the story is deeply personal and familial. The plot is set in motion when her younger sister is abducted by an alien species known as the Greys, who implant a special chip in the sister's brain. This traumatic event drives Halle to take action, and she stands alongside her friends to rescue her sibling and uncover the truth about the alien presences on Earth. Her love for her sister and her resolve to save her are key drivers of her involvement in the escalating conflict.

Within the group of friends which includes Ray, Anna, Tyler, and Eisuke, Halle is an integral member, united with them in the face of mysterious and dangerous incidents at their school. Her relationship with her abducted sister serves as the emotional core and the initial catalyst for the group's adventure. She also looks to her professor, Suguru Yoake, as a trusted authority figure and the person they turn to for guidance when mysterious events begin to unfold. The film focuses on the groups shared journey, and Halle’s personal development is closely tied to this collective struggle, as she moves from being a studious individual to an active participant in confronting an extraterrestrial threat. Information regarding notable superhuman abilities or unique skills specific to Halle is not available, as her role is defined more by her personal resolve and academic background than by any overt combat or supernatural powers.