One Piece Chapter 5, page 12-13: CHAPTER 5: THE KING OF THE PIRATES AND THE MASTER SWORDSMAN

Kuina sits down on the deck, looking melancholy, and says, "I'M THE ONE WHO'S FRUSTRATED..." Zoro looks up, confused: "HUH?" Kuina explains, "WHEN GIRLS GET OLDER, THEY BECOME WEAKER THAN THE BOYS. PRETTY SOON YOU'LL ALL BE STRONGER THAN ME. ZOLO, YOU'RE ALWAYS SAYING......THAT YOU'RE GOING TO BECOME THE WORLD'S GREATEST SWORDSMAN... DAD SAYS THAT GIRLS CAN'T BE MASTER SWORDSMEN... YOU'RE LUCKY YOU'RE A BOY, ZOLO... I WANNA BECOME THE WORLD'S GREATEST SWORDSMAN TOO!! BUT I'M STARTING TO GET BREASTS... I WISH I WAS A BOY..." Zoro gets angry and yells, "WHAT ARE YOU CRYING ABOUT! YOU BEAT ME!! THAT'S NOT FAIR! BEATING YOU IS MY DREAM!

Zoro continues to lecture Kuina, shouting, "SOMEDAY I'LL BEAT YOU BECAUSE I WORKED HARD, NOT BECAUSE YOU GOT WEAKER!! IT'S GOT NOTHING TO DO WITH BEING A BOY OR A GIRL!! I'M TRAINING ALL THE TIME TO BEAT YOU! YOU'RE MAKING ME LOOK BAD!" Kuina listens quietly. Zoro then proposes, "LET'S MAKE A PROMISE TO EACH OTHER! SOMEDAY, ONE OF US WILL BECOME THE GREATEST SWORDSMAN EVER!! WE'LL FIGHT EACH OTHER FOR THE TITLE!" Kuina, crying tears of joy, smiles and calls him a "YOU IDIOT! YOU'RE TOO PUNY!" Zoro firmly declares, "IT'S A PROMISE!" as they seal their pact.