Heero,the protagonist of the series,was trained to be a pefect soldier at a very young age. He is infact the son and protege of first-class assassin Adin Lowe(btw..Heero's real name is Adin Lowe Jr).When Adin died, Heero was handed over to Dr. J to further hone his MS piloting skills. When he was as finely tuned a pilot as could be wished, Dr. J sent him to infiltrate Earth as a part of Operation Meteor. Heero has little if any emotions and a suicidal attitude.Heero carries out his missions seriously and will not hesitate to kill if necessary. Undoubtfully, he is the best Gundam pilot among the 5 Gundam boys and the only one capable of mastering the "zero system".However,with little emotion he has, Heero developes a strong relationship with Relena Peacecraft.