Movie
Description
Hiroomi Nase belongs to the esteemed Nase family, Spirit World Warriors dedicated to fighting supernatural beings called youmu. Born on July 21, he stands 178 cm tall, sporting black hair in a bowl cut and green eyes. He constantly wears scarves or mufflers because his supernatural abilities render him highly sensitive to cold; these scarves also act as offensive weapons against youmu upon contact.

A pivotal junior high incident involved his elder sister Izumi, then the family head, assigning him to eliminate the half-youmu Akihito Kanbara. During this mission, Akihito's youmu side manifested, severely injuring Hiroomi and leaving permanent scars on his back. This event prompted the Nase family to increase surveillance on Akihito, though Hiroomi eventually formed a genuine friendship with him.

Initially a third-year high school student, Hiroomi joined the Literary Club alongside his younger sister Mitsuki and Akihito. He frequently displayed a playful side, teasing Akihito by calling him "Akkey." Hiroomi harbored a deep protectiveness toward Mitsuki, exhibiting a sister complex that included blushing or nosebleeds when she addressed him affectionately. Despite frequent bickering, their bond remained strong, and he often withheld information to shield her from worry.

During the events of the Mirai-hen films, following Izumi's disappearance, Hiroomi underwent substantial development. He assumed leadership of the Nase household, adopting a more serious and reserved demeanor. His responsibilities expanded to include extensive paperwork and clan management, reducing his social interactions. In this period, he confronted Izumi, who was under a parasitic youmu's control. Hesitant to harm her due to lingering affection, he later acknowledged his failure to support her adequately. Their final confrontation ended in reconciliation, with Hiroomi expressing regret for not standing by her sooner.

His abilities focus on "Glaciate Barriers"—defensive or containment fields effective against youmu. As clan head, his proficiency improved significantly, enabling him to multitask by maintaining barriers during other actions. His scarf remains his primary offensive tool, capable of disintegrating youmu through touch or ensnarement. The power tied to these abilities intensifies his cold sensitivity, a common Nase family trait.

Hiroomi's relationships extend beyond his family. He gradually came to view Mirai Kuriyama as a younger sister, sympathizing with her struggles and adopting a protective stance. His dynamic with Akihito evolved from surveillance target to trusted friend, culminating in emotional relief upon Akihito's return after Mirai-hen. In the film's conclusion, he tearfully embraced Akihito, underscoring their bond.