Roronoa Zoro was born in the east blue, one of the four seas in the world. In one part, the east blue is known as the weakest sea. Zoro's parents were Tera and Roronoa Arashi. His father and mother were killed when pirates attacked and were able to run away. He made it to Shimotsuki Village where he trained. He was the second strongest student there. Only second to the daughter of the Shimotsuki Koushirou, Kuina. Kuina would always defeat Zoro when he would duel her with wooden swords. So he trained more and more to get strong enough to defeat Kuina. He kept losing even though he kept training harder, so he wanted to fight her with real katanas, but he still lost again even though he fought her with real katanas. Kuina had won all of her fights against Zoro. So he promised Kuina after the fight that one day one of them would become the world's strongest swordsman in the world. The next day, he trained and trained until one day, when one day he heard some tragic news from the headmaster of the dojo. The headmaster told Zoro that Kuina had died. He started crying and he asked the headmaster if he could have her sword because he made a promise that he would become the greatest swordsman in the world and the headmaster gave him Kuina's sword and then his journey began, becoming the strongest swordsman in the world.