The pilot of the Wing Gundam, the boy known as Heero is the most grim and serious of the Gundam pilots. His true name is unknown, but for this mission of revenge he has been code-named after the martyred leader of the space colonies. Raised by the scientist Doctor J, Heero has been trained since childhood to be a ruthless killing machine, equally proficient in mobile suit piloting, personal combat, demolitions, and computer hacking.

Though Heero's upbringing hasn't quite managed to squeeze all the compassion out of him, he is nonetheless callous towards his allies, and cold-blooded towards his enemies, and almost suicidally careless of his own life. His unexpected reluctance to kill Relena, after she discovers his identity, is the first step in Heero's gradual reclamation of his own humanity.  Heero pilots the Wing Gundam Zero after the Wing Gundam is destroyed.