Hiro Shishigami

Hiro Shishigami (獅子神 皓, Shishigami Hiro) is the main antagonist who eventually becomes a deuteragonist. He is a high school student and a mass murderer after becoming a cyborg.

Appearance
Hiro was a potentially tall young man with short navy hair that has bangs hanging on the right side, deep brown eyes, he is shown to be at least of medium height and he has a particularly pretty face to the point that he attracts a lot of attention from females around him.

Personality
Although Hiro appears to be a kind and polite boy, he was a selfish person who uses his cybernetic power to murder people that annoy him, or slaughter families to make him feel alive. He believes that with his new power, he was now above everyone else, and no one on the planet can stop him. However, despite his homicidal desires, Hiro is not completely monstrous. He was shown saving and helping people at multiple points, both unprompted and also as guided by those he cares for. This suggests that Hiro has some humanity lingering in his system, as he was also shown to love his mother dearly and intensely cares for a close few around him, such as Naoyuki Andō or Shion Watanabe. Although Hiro's cybernetics might contribute his sociopathy, other factors such as living with his mother in a rundown apartment and his father having another family, the frustrations of high school life, and dealing with bullies might have also be responsible for becoming the person he used to be.

Plot
Hiro was an average high school student who was unfortunate enough to be caught in the blast of a UFO explosion in a park. The extra-terrestrials, not intending to kill any intelligent life, decided to remake Hiro, replacing his organic body with a cybernetic one. This results in Hiro gaining extraordinary powers. Ichirō Inuyashiki, a salaryman recently diagnosed with stomach cancer and who was also in the park at the same time as Hiro, was caught in the UFO blast as well and his body was also remade with cybernetics.

With his new powers, Hiro freed Naoyuki Andō and he decided to break his friendship with Hiro.

Police eventually discovered Hiro's involvement in the home invasion murders and arrived at his mother's apartment to arrest him. He escaped, but his mother Yuko Shishigami and the Japanese public learned that he was a mass murderer. Unable to deal with the public anger, Yuko committed suicide. An enraged Hiro traveled to his father's home, where he gunned down several reporters interviewing his father before fleeing the scene. Afterwards, he killed around 50 Internet trolls who had mocked his mother after her death, shooting them through their laptops and smartphones.

Hiro would live with Shion Watanabe and her grandmother for the next two months. At Shion's insistence, he used his powers to heal the sick and injured in order to atone for his murders. However, this came to an abrupt end with a Special Assault Team raid on the apartment. Hiro killed the SAT members, but Shion and her grandmother were both shot dead. He healed them, took them to safety, and headed to Gokokuji Police Station to seek revenge.

Upon arriving at the police station, Hiro killed the guard at the door before storming the station and murdering dozens of officers and staff. He shot the last surviving officer in the leg so that he could tell others of Hiro's revenge. When Hiro left the police station, he was immediately attacked by more police and SAT forces. The SAT managed to knock him out with heavy gunfire, but his cybernetic body's systems took over and killed the police and SAT with laser fire. Hiro murdered a total of 85 people - 51 regular police and 34 SAT officers - at Gokukuji Police Station.

Abilities
Like Ichirō Inuyashiki, Hiro gains a cybernetic body, weapons and unnatural powers. These powers and weaponry are the same as Inuyashiki's.
 * Superhuman Strength
 * Superhuman Durability
 * Laser Blasters 
 * Mini Rockets (live-action, replaced Laser Blasters)
 * Telekinesis
 * Technokinesis and Technopathy
 * Jet-Propelled Flight
 * Self-Destruction Bomb (inside Hiro's body)

Manga and Anime
When a massive asteroid threatened the planet, Ichirō Inuyashiki ventured into space in an attempt to destroy it, but didn't have enough water to sustain his laser weapons. At the last minute, an injured Hiro arrives to help, wanting to save the lives Ichiro cherished, such as his foster father, Shion Watanabe and her family. After running up a simulation, he arrives at the conclusion that his self-destruct mechanism would be powerful enough to destroy the asteroid. Hiro kneels down at the asteroid and closed his eyes while Ichiro pushed both of his eyes before moving away from him. Hiro self-destructs in a massive, yet brilliant explosion, though the blast was not enough to destroy the asteroid.

Left without other alternatives, Ichiro activated his own self-destruct, breaking the asteroid into pieces small enough to burn up upon entering Earth's atmosphere. However, despite the good deed Hiro had done, the explosion wasn't enough to fully destroy the asteroid, forcing Inuyashiki to sacrifice himself by activating his own self destruct system and causing a second explosion that fully destroys the asteroid.

Etymology

 * The name Hiro means "white, clear" (皓).
 * Hiro's surname Shishigami means "lion" (獅子) (shishi) and "god, deity" (神) (kami/gami).

Trivia

 * Hiro was a big fan of the One Piece manga series.
 * Takeru Satoh (the actor who played Kenshin in Live Action Samurai X) plays Hiro in the live-action movie adaptation of Inuyashiki.