"It's not fair!" Kuina said, crying. "You're a boy, you'll get stronger. I'm already growing out from my chest." She grabbed it firmly. "If I were a boy like you…" Zoro growled.

"So what," Zoro told her. "You're still strong! We both can become great if we try hard!" The young swordsmen in training shook hands, reaffirming their relationship. However, later that night young Kuina would fall a terrible fate. As she went in for a bath, her father came in.

"Kuina," He said in a low tone. "About earlier…"

"No, it's fine."

"No, it isn't. You aren't fit to be a swordsman." She tensed up. "Father, all of a sudden you come out with this! Why?" She began to tear up. "Listen, there's only one role for a woman, and that's tending to what the men of the house ask her to." He glared at her. "Your mother's been gone for a while now," He told her. "I've had dreams about her being alive and the three of us making our dojo prosperous…" Kuina went to her father.

"I miss her, too." The two hugged. "It's been so long since I've had the touch of a woman on me…" He began to stroke Kuina's shoulder. "The smell, the soft, sensual touch…" Kuina noticed what was going on.

"Father." Koshiro started to panic.

"Sorry, Kuina. I lost myself for a minute. She was still wearing her towel. Her chest stuck out from under it. "My, you've grown well." Koshiro said, genuinely being caring. "I hate it…I can't be a proper swordsman if my chest grows big like this.

"No, it's fine. You're a woman, it's perfectly normal to have such a nice bust, especially at your age…" Kuina held onto it, looking sad. "I can't be a swordsman because I'm a woman, father! You said it yourself!"

"I was wrong for saying those things," Koshiro said, moving in on his daughter. "You're as strong as any man." Kuina looked him in the eyes. Suddenly, she felt her chest being groped. "Oh my, this is such a great chest. Well-crafted, like the Wado Ichimoji."

"Father!"

"Ah, I've done it again!"

The next day, a truly more terrible fate would befall Kuina. This time, yes. Zoro appeared and proceeded to spar with his rival once more. The two battled with Shinai, giving it their all. And to no surprise, Kuina won once more. The two lay sweaty on the floor. Zoro, looking at his rival saw her chest through her shirt. Something was poking out.

"Those are her…" Zoro turned away, blushing. "Try again after lunch?"

"Sure."

Zoro couldn't get his mind off Kuina's developing womanhood. At the next duel, Kuina was easily countering the distracted student.

"What's the matter," She asked. "You're never this rusty after lunch." Zoro was staring at her chest, seeing a slightly exposed lump of softness and joy. He blushed. Kuina jabbed him in the stomach.

"You pervert! You were looking at my chest, weren't you?!" Zoro looked away, embarrassed. "This chest…" She ran away. Zoro went after her. They went into the forest, isolated from the rest of the town. "Kuina! I'm sorry!" Zoro looked around for her. Suddenly, something came from behind.

"Got you." It was Kuina, who looked a little off. "You noticed my ailment, right?" She put his hand on her chest. "Well? How do you like it? It's a sign of my failure to be the greatest swordsman."

"Stop saying that!" Zoro yelled. He then started to feel it more and more. "It's so soft and squishy…" He then touched the other breast with his right hand. Suddenly, Kuina fell down on the ground, enticed by the feeling. "Kuina, are you hurt!?" She smiled at the moss-headed boy.

"No, I'm fine…better than ever." She went to Zoro and began to kiss him. The boy had never felt anything like it. The thrill of swordplay and defeating his opponents were different compared to it. There was a warm feeling within that grew with each passing second. Zoro felt something from Kuina's chest. "Are those her…" She took off her shirt.

"Keep going, Zoro…" He backed away. "Wait, why are you-"

"I need you now, Zoro. I need to fulfill my duty as a woman…" She went to him and yanked off his drawstring, pulling down his pants. There, his untouched innocence lingered, dormant. "A man is also someone who can make a woman feel good," Kuina said, touching his balls. Zoro tried to move away, but Kuina overpowered him. "You still can't beat me…but you're about to find out my one weakness…" Kuina's warm hands made Zoro's member grow. "My penis is getting…" He couldn't finish his sentence, as he was receiving a blowjob from Kuina.

"This feels…amazing."

"Do it, Zoro," She thought. "Shower me with your manhood!" After a minute of sucking, he did just that all over the girl's chest and face.

"I peed all over you," He shouted.

"No, you showed your worth as a man!"

"I did?" "Yes, and it's time for the true test of adulthood." She pulled down her pants and panties, showing off her genitalia. "What am I gonna do-" She laid down and spread her legs. "This is a vagina," She explained. "You have to put your penis in it."

"My what?!"

"Your penis. Your penis goes in here, like a sword goes in its sheath. Come here and show me your skills, swordsman!" Zoro appeared inspired. "Oh, I think I get it." He went to Kuina and started to jam his penis into the frontal labia. "It's not going in…"

"Harder."

"Harder!"

"HARDER!" Zoro finally sheathed himself in Kuina, blood slowly trickling down. "Oh, I'm sorry! I cut you with my penis!"

"No, you made your mark, swordsman. Now continue!" Kuina guided him through the mysterious and alluring art of intercourse.

To master it, one must be in sync with their partner. With each movement and thrust, one must be able to withhold their composure and endurance. As the feeling intensifies, they'll begin to feel more and more heavy. But they must wait until their partner is in unison with their feelings at the exact moment. But in exchange for one's patience, they are rewarded with a sensation that signifies life, harmony, love, joy, serenity and light.

The Six Principles of Ejaculation.

Young Zoro and Kuina experienced that on their first attempt, and would continue to do so as the days passed, alternating between their training of the sword, and their desires of lust.

However…

The first day proved to be dangerous, as it was the moment where Kuina was signified as a woman, unable to become a great swordsman, let alone a dojo master. Within her, came a new threat, one that would prove to be much graver than a developing chest or being told her worth. Her strength deteriorated with her illness. And suddenly, she found herself to be growing slower and slower as a result. She could barely defeat Zoro.

One day, her torso grew notably larger. And rounder. She screamed loudly. When Koshiro came to the scene, he saw that his daughter was pregnant.

With the child of Roronoa Zoro.