Episode 19

"Past of the Three Swords! The Promise Between Zoro and Kuina!" is the 19th episode of the One Piece anime.

Short Summary
While Usopp and Luffy fool around with the ship's cannon one day, Zoro dreams about his childhood and the promise he made to Kuina before her untimely death.

Long Summary
While out at sea, Luffy found a box of cannonballs in Going Merry Storeroom and brought it onto the deck. Nami finds a place on the map where they can go to practise shooting them. This gets Luffy all excited. This episode flashes back to Zoro's childhood.

Zoro was a doujouyaburi, collecting dojo signboards. When Zoro challenges Koshiro, the owner, he accepts, but offers his daughter Kuina as his opponent. Zoro grabs a huge amount of shinai (several in each hand, and three in his mouth) to prepare. Even before the match begins he has dropped 2/3 of the ones in his mouth.

Zoro is able to block the first overhand strike with his shinai collection. The second vertical strike is more powerful and knocks Zoro back to the ground, causing him to drop all of the weapons.

Zoro gets up and strike a great "two sword/shinai technique" pose. This causes visible surprise in the master and his daughter, who ask if he has been trained in kendo before. Zoro explains that this is the first time he's ever held shinai.

Zoro charges towards Kuina, smack one hit right in between the eye, Ipon! Zoro loses. Zoro joins the dojo and swears that he'll beat Kuina one day. Kuina tells Zoro that he's years early to be able to fight with two swords.

A training montage is shown where Zoro works himself to exhaustion on a daily basis, regardless of it being hazily hot or chillingly cold. In addition to smacking a training post, Zoro is seen competently fighting off adult male members of the dojo.

One distinctive scene is Zoro standing on a pair of rocks with a stream running in between them. A bite in his mouth is attached to a large boulder with a piece of rope, and he is holding that position to strengthen his biting muscles (as well as legs and torso). Later when the montage shows him doing this in the distance, Kuina is seen watching him train from the shadows.

It then shows Zoro losing a two thousandth consecutive fight to Kuina. She then calls him weak. The younger male students comment that he isn't weak, and is strong and beating adults. They then ask Koshiro if he is giving his daughter special training on te side due to favouritism. He explains that he isn't, and that she is also getting stronger.

Kuina later overhears her father discussing with another man that a female sword fighter has many barriers, and that he would not let her inherit the dojo. This visibly angers her and she breaks in (revealing her eavesdropping, which her father criticizes) and claims that she will become the strongest and deserves to inherit it.

Koshiro replies calmly that a woman would not be able to become the world's best. This causes her eyes to glaze over in shock and she walks off, stricken.

Kuina is seen apparently crying sitting by the road in the middle of the night, and Zoro approaches and challenges her, carrying a pair of real metal katana instead of the wooden shinai they had used in previous battles. Kuina accepts the challenge, and goes into her family's shrine and retrieves the Wado Ichimonji for their duel.

In their first exchange Zoro manages to cut off some of her hair with his second blade. After fighting for a while, Zoro is visibly gasping while Kuina is not breathing heavily at all. She comments that two swords must be heavy and that he is still lacking stamina.

In response's to Zoro's usual rude reply, Kuina lunges in and is able to disarm both of his weapons in a single upward swing. As he lies helpless on his back, she goes in for the finishing blow, but intentionally plunges the Ichimonji into the ground an inch from his cheek.

Still undefeated, after the fight Kuina consoles Zoro, telling him that as they grow older, Zoro will eventually surpass her. Kuina tells Zoro that a woman can never be the world's greatest swordsman. Zoro disagrees and challenge her to compete and see who between them will become the world's greatest swordsman. Kuina accepts.

Kuina is seen continuing to train enthusiastically while beating an adult male student. Zoro is seen doing another strange exercise by himself where he holds a dumbbell in his mouth while pulling down a pair of ropes slung over a treebranch (used as a pulley) to lift a pair of boulders, to increase his stamina. It is at this point when some younger students approach with gaunt looks on their faces and tell him that Kuina is dead.

Kuina had apparently died falling down the storage room stairs while looking for her katana whetstone. After her funeral, the master thanks Zoro for joining the dojo and motivating Kuina to train hardest. Zoro ask for Kuina's katana. He swears that he'll keep the promise made with Kuina, to become the strongest swordsman in the world. The master leaves Kuina's soul and dreams with Zoro. Eight years have passed and it's time for Zoro to leave the dojo to fulfill that promise.

Back to the present, Luffy and Usopp practice shooting cannons, Usopp hits the target in a single try. Unknown to them, they have hit someone Yosaku. Later, back in the cabin, the Mugiwara Pirates are having a discussion about adding a new crew member, either a musician or a cook. When they hear a commotion on the deck, Luffy goes out to check. Johnny, whose partner was hit, is seeking revenge. Zoro recognise Johnny's voice. They were friends back in the days when he was a pirate hunter. Zoro asks Johnny why he is alone and where Yosaku is.