Yuji Fuse, known as Hacker, operates within the government's elite Special Security Force, combating terrorism. He specializes in computer hacking and technical operations, while also possessing significant direct combat skills and proficiency with heavy weapons. His enormous muscular physique facilitates active participation in firefights alongside his technical duties. Hacker is routinely partnered with Reika "Peace" Yogawa, the unit's explosives expert; their close operational pairing later reveals Peace's romantic feelings for him.

During a critical mission escorting Red May leader Tachihara on a highway, the powerful psychic antagonist Lucifer intercepts them. Lucifer immobilizes Hacker, forcing him to witness Peace's brutal rape and subsequent death. Attempting retaliation, Hacker aims his weapon at Lucifer, only for the psychic to shatter it telekinetically. When fellow unit member Angel arrives, Hacker remains silent and unresponsive, displaying a grenade in his hand. Lucifer remotely pulls the grenade's pin and psychically locks Hacker's body, preventing him from discarding the explosive despite Angel's warnings. The grenade detonates in his grasp, killing him instantly; Lucifer is later seen holding his severed head. Circumstances suggest Lucifer may have psychically killed Hacker prior to Angel's arrival, using his body as a puppet, though this remains unconfirmed.

The manga adaptation presents a divergent fate: Hacker is killed by another psychic hunter, Freya, during an unspecified encounter, entirely omitting the highway confrontation with Lucifer, Peace's death, and his controlled detonation. Across both versions, Hacker's narrative focuses solely on his technical skills, combat role, partnership with Peace, and demise during operations against terrorists and psychic threats, providing no significant character development or personal backstory beyond his function within the Special Security Force.