TV-Series
Description
Tetsuro Arahabaki, son of Beruhren Corporation CEO Soichiro Arahabaki, endured invasive experimental procedures that implanted the "Harmony" device within his spinal cord and medulla oblongata. This device allows him to remotely control the cybernetic bodies of Extended individuals by hijacking their auxiliary brains. His original limbs were deliberately damaged to prevent mobility, and his vocal cords were severed, leaving him mute without mechanical aid. He escaped Beruhren's captivity, though the corporation relentlessly pursues him.

Physically, he appears as a young teenage boy with a slender build, hazel eyes, and straight black hair reaching his neck. Cybernetic prosthetics replaced his limbs after the intentional laceration of muscles and nerves. Bandages conceal surgical scars from his vocal cord severing around his neck, and his fugitive status leaves him without distinctive clothing.

Personality-wise, he harbors deep resentment toward those responsible for harming him and other children. His persistence drives noble intentions, often a desire to protect others, though impulsiveness sparks rash decisions that escalate situations. For instance, he defied Juzo Inui’s warnings, using Harmony to control Juzo’s body in an attempt to rescue children targeted by Beruhren-affiliated attackers, inadvertently worsening conflicts and endangering allies. Despite missteps, he demonstrates kindness and commitment, such as assisting Mary Steinberg in locating her brother by identifying a stolen component linked to him.

His development centers on evolving use of the Harmony device. Initially limited to controlling one Extended body at a time, leaving his physical form vulnerable, he sought refuge with Resolver Juzo Inui after escaping Beruhren. Mary provided cybernetic limb and vocal replacements. His abilities grew significantly; he learned to control his own sub-brain, enhancing combat effectiveness, and later mastered simultaneous control of multiple Extended bodies. During a confrontation with the spider-like Extended Ende, he wielded Juzo’s body as a firearm to defeat her, showcasing increased proficiency and tactical adaptation. However, his actions often carry consequences, like violating agreements with Juzo by using Harmony on EMS agents to deliver cigarettes, highlighting his recurring struggle with ethical boundaries.

His relationship with Juzo shifts from dependency to partnership. Early on, Juzo protected him under a contractual agreement, but Tetsuro gradually asserts his autonomy, insisting Juzo trust him as a collaborator. This dynamic culminates in his request to work alongside Juzo, symbolizing his transition from victim to active agent. His moral compass is tested when he brokers a deal with Professor Wachowski to unlock Juzo’s latent abilities in exchange for safety during a hostage situation, reflecting his willingness to confront complex dilemmas for the greater good.

Tetsuro’s backstory reveals he once funded the anti-Extended group Spitzbergen to undermine Beruhren’s tyranny, clarifying his core motivation as opposition to corporate exploitation rather than prejudice against Extended. This history underscores his commitment to dismantling systems that treat individuals as tools, a theme reinforced through his rejection of Hugh Cunningham’s dehumanizing ideology.