One Piece Chapter 5, page 8-9: CHAPTER 5: THE KING OF THE PIRATES AND THE MASTER SWORDSMAN

A flashback begins as young Zoro remembers a promise. He lies defeated on the ground of a dojo, crying out "UGH!" as the crowd cheers, "KUINA WINS AGAIN!!" Other young dojo students gossip about his defeat, saying, "ZOLO IS 0 FOR 2000 AGAINST KUINA!" and "'TWO-SWORD ZOLO' LOSES!!" Kuina stands over him, holding her wooden sword, and says, "PATHETIC... KIND OF WEAK FOR A BOY, AREN'T YOU?" Three young dojo boys defend Zoro, saying, "HEY! ZOLO'S NOT WEAK!" and "YEAH! HE'S THE STRONGEST IN OUR DOJO! HE'S EVEN STRONGER THAN THE GROWN-UPS!" However, they also grumble about Kuina: "SHE THINKS SHE'S SO GREAT JUST BECAUSE SHE'S THE SENSEI'S DAUGHTER!" and "KUINA MAKES ME SO MAD! DARN!" Kuina walks away, saying, "THAT SO? WELL, HE'S NOT AS STRONG AS ME! EVEN IF HE CAN USE TWO SWORDS, HE'S STILL WEAK! LOSERS SHOULD LEARN TO SUFFER DEFEAT IN SILENCE.

Young Zoro complains to his master, Shimotsuki Koushirou, accusing him of favoritism: "SENSEI! ARE YOU TEACHING HER SECRET TRICKS BECAUSE SHE'S YOUR DAUGHTER!? IT'S NOT FAIR!" Koushirou chuckles and replies, "OF COURSE NOT! LOST AGAIN, EH, ZOLO? IT'S ODD BECAUSE YOU ARE ACTUALLY VERY STRONG." Zoro demands, "SENSEI! WHY CAN'T I BEAT THAT GIRL!?" Koushirou gently reminds him, "DON'T FORGET THAT KUINA IS A LITTLE OLDER THAN YOU." Zoro protests, "BUT I CAN BEAT GROWN-UPS!" Later, Zoro trains alone at night, striking a training post repeatedly with his wooden swords. He yells in frustration, "DARN! I CAN'T KEEP LOSING TO THAT GIRL! I'M GOING TO SAIL THE SEAS AND BECOME THE GREATEST SWORD MASTER IN THE WORLD!