Rei Enna

Zero (his real name "Rei" is the kanji representing number 0) lost his father when he was very young and was raised by his mother on a remote colony. Cheerful and optimistic to the extreme, Zero hides his fears and refuses to ever be depressed. His straightforward and optimistic personality sometimes grates on others. A bit thickheaded, he's not the smartest candidate, but he can move with the best of them. His piloting abilities are like carbon that hasn't yet been formed into a diamond. Zero hasn't yet mastered his EX. His number is 88 and his Repairer is Kizna Towryk. Source: Wikipedia