Roronoa Zoro
Biography
Zoro is a swordsman who aims to be the strongest in the world. As first mate of the Straw Hat crew, he takes responsibility when Luffy falters and fights in just about every major arc. What differentiates him from other swordsmen is that he uses three swords (one in each hand and one in his mouth), but once he was a two-swords user. That story is here.
History
Prelude
As a boy, Zoro aspired to be a master swordsman in an as-of-yet unnamed village in an as-of-yet unnamed area of East Blue. With his "Nitoryuu" (Two Sword) style he could defeat anyone and anything that opposed him, save one obstacle: The daughter of his sensei, Kuina. Kuina was incredibly strong, beating Zoro's two swords with only one, and the two fought over 2,000 matches during their rivalry.
Action
Angered and embarrassed at his inability to best Kuina, Zoro challenged her to their first 'duel', one with real swords. All it took was four manga panels for Zoro to lose, but it was Kuina who was most depressed. Her father had claimed that a woman could never become the greatest of swordsmen, and so after the duel she cries at her fate.
Zoro berates her, telling her that she is his goal! Both of the two children make a pact that one of them would become the world's strongest swordsman, and then they would fight each other for the title. With a clasp of hands and a vow of "Yakusoku!" the deal was sealed.
But it was not to be. The next day Kuina died with a tumble down the stairs, and Zoro burst onto the scene clutching his swords. Lividly he screamed that Kuina couldn't break her promise. She couldn't run away! Tearfully he asked his sensei, Koshiro, for Kuina's sword, and so received it with his vow: He would become such a marvelous swordsman that even Heaven would know his name!
Roundtable
GoAnderson: Zoro's past is the shortest of all the Straw Hats, and so that leaves much to wonder about certain details. Where in East Blue did he grow up? Did he even live in East Blue before setting off on his journey? Sanji, we know is from North Blue. Does this mean Zoro, too, was from a different Blue? Comments?