Chiro is the leader of the Shuggazoomian Hyperforce. He's 13 part-way through the first season, he turned 14 in A Man Called Krinkle. According to his collector's card, he is a male weighing 125 lbs and is 5' 7". He pilots the Torso Tank 1, the Super Robot's torso, and his weapon mostly consists of the Power Primate's power.
As explained in the theme song, Chiro was exploring the outskirts of Shuggazoom City when he found The Super Robot. He gained the power to posses the Power Primate, awakened the robot monkeys sleeping inside, and became the Hyperforce's leader. He's become a close friend to all the other members of the Monkey Team in his adventures with them.
Other than that, many parts of Chiro's past still remain a complete mystery. His backstory has only been touched a few times. In the episode Skeleton King, Chiro and Gibson come across a room filled with various toys and clothing. Chiro comments grimly that the stuff is his "from a long time ago". In Night of Fear, Chiro transformed into a small child wearing an outfit previously featured in the room. Apparently, his greatest fear is being weak and powerless. From these points, it would seem that Chiro may have a hard past. According to some of the staff, Chiro was a latchkey kid.
Since so little is known about Chiro. He becomes the subject of many fan-theories. Numerous fan fiction set before Chiro found the Super Robot portray Chiro as an orphan with abusive parents, or his parents died and his relatives occupied Chiro's house and ill-treated him, or Skeleton King made his parents as his prisoners or sent them to some other planet or galaxy. Some believe Skeleton King killed his parents. Some even believe that Skeleton King's related to Chiro in some way, the most common form of this theory being that he is Chiro's father.
In the episode, I, Chiro, Antauri dies and his soul goes into Chiro's body. Which in turn, turns Chiro into a monkey, until the next 2 episodes where Chiro turns back to normal.
Being the leader, he's still learning about the job and Power Primate. He's very outgoing and tends to act like every typical 13-14 year old boy: loves video games, the arcade, and attempts to impress girls on many occasions. He cares deeply for his friends. Chiro is at times very impulsive and stubborn, a trait that tends to get him (and everyone with him) into trouble, such as in Pit of Doom. He also doesn't have the natural ability to fly, so often times uses a jet pack given to him in the same episode.
Chiro is a big fan of the Sun Riders, a group of television superheroes with real powers.
As stated previously, he has unprecidented control of the Power Primate and also the Chosen One. His control of it in Versus Chiro led Antauri to remark: "Chiro, I have never seen such control of the Power Primate. Not even by my own masters." Being the Chosen One also means he's destined to fill Mandarin's hypothetical shoes. Unfortunately, this often goes to his head.
Chiro's powers come from the Power Primate entity inside him. He can utilize Electrokinesis, as seen in the attacks Lightning Kick and Thunder Punch. He's also seen utilizing the Power Primate for combat.
- Thunder Punch: An electricity based punch. Used very often.
- Lightning Kick: An electricity based kick. Used often, but not as often as "Thunder Punch" after the first couple seasons.
- Chiro Spearo: A bolt of lightning thrown by Chiro. Again, not used as often after the first couple of seasons.
- Monkey Mind Scream: An energy based attack shot from the mouth. Used more commonly by Antauri.
- Monkey Fu: A burst of green energy that focuses into a beam or radiated out over the whole body.
- The Inner Primate: A green gorilla like force field around Chiro.
- Monkey Blow: A blow can push the enemy. It's like Monkey Fu except it comes from hands, shown in Skeleton King.
- Martial Arts: The Hyperforce train him in fighting.
- Primate Aura: Chiro absorbs the inner primate and radiates with green energy. Used only in Antauri's Masters.
Antauri: Very Close. They share a father-son bond, as well as a mentor-appentice bond. Antauri serves as Chiro's mentor in the spiritual arts as well as being an effective leader. Chiro had endless trust in Antauri and did everything he could to revive him. In turn, Antauri believes that Chiro is the Chosen One.
Nova: Close Friends. They share a mother-son bond at times as well as a bond of an older sister and younger brother, but she's also shown as a close friend to him. She mentors him in fighting
Sparx: Close Friends. They tend to pull pranks and such on others and share common interests. Sparx is something of an older brother and he sympathizes with Chiro when both had to confront their underwater-related fears.
Otto: Close Friends. They share common interests, as with Sparx. One of those interests appears is mechanics. They both also fool around at times.
Gibson: Friends. They seem to have the least deep relationship. Often, Chiro will avoid Gibson's lectures and such. Despite this, they share deep moments, such as Gibson comforting Chiro after the battle with Sun Riders, saying that it was what they stood for that made Chiro want to become a hero. Another moment, was where they go to rescue the others from the Citadel of Bone, he was with Chiro when they discovered a room filled with all of Chiro's former possessions. They may mean that Gibson is the only one who had this rare glimpse of Chiro's past.
Jinmay: Girlfriend. They fell for one another when he rescued her.
- In Skeleton King, Gibson and Chiro ran into a room filled with his childhood belongings. When he said they were his, he added, "From a long time ago." This implies he had a rough childhood. This is further added to in Night of Fear when he turned into a small child.
- Chiro's voice actor Greg Cipes, voiced Beast Boy in Teen Titans & older Kevin Levin in Ben 10. In Teen Titans, Beast Boy is Terra's boyfriend. Kevin is Gwen Tennyson's boyfriend. Ashley Johnson voiced both Terra and Gwen.
- His name derived from the japanese word "ichiro", which means "hero". It might also be derived from the word "Ichirou" which means "first son".
- Surprisingly enough, the name "Chiro" has a European equal "Chairo", which means "sacred name" in Spanish and Greek. In the same area, written in an ancient manuscript called the Book of Kells, its most famous page, the "Chi-Rho" page, gives the nickname of Jesus Christ, the foretold savior of Christianity who gave his life for the sins of world, resurrected three days later, and it's said to come again someday. Rather fitting for this character, as he's Shuggazoom's foretold equal, the Chosen One, in several ways.