ZoSan

ZoSan is the slash ship between Zoro and Sanji from the One Piece fandom.

Canon
Zoro and Sanji didn't really like each other at the beginning. They fought and quarreled a lot, were annoyed by just each others personalities. But with time they grew closer and although they still don't agree in many things, they care about each other, even if they wouldn't say that out loud.

Baratie Arc
This is the arc, where Zoro and Sanji meet for the first time, though they don't share a longer conversation yet.

Sanji, back then, was an assistant chef in the Baratie, an ocean-going restaurant. Luffy, Zoro, Nami and Usopp needed to stay there for a while, because of an accidental, extensive damage Luffy caused to the resturant's ship.

After some time there, Zoro and Sanji share their first, short conversation. Zoro states that his goal is Grand Line too from now on, since he just learned that Hawk Eyes - the strongest swordsman in the world - is there too (and Zoro aspires to become the strongest swordsman in the world himself). Sanji comments it saying that Luffy and his crew are a bunch of morons, which probably are the ones dying first. Zoro says that he's right, but he didn't have to say the part about 'morons'. He says that from the time he decided to become the strongest swordsman in the world his life and death doesn't really matter to him and that he himself is the only person who can call him a moron. Then their conversation ends.

Soon afterwards the Baratie is attacked by Don Krieg's crew, which was also chased by Hawk Eyes - the same person Zoro wanted to find and take him on. After Zoro is beaten by Hawk Eyes and lands in the sea, Sanji recalls his and Zoro's previous conversation. Sanji calls Zoro a 'shitty idiot' in his thoughts, claiming that 'he totally lost his mind and he could just give up his dreams, he didn't have to die for them'.

Arlong Park Arc
During the battle with Arlong's men, Zoro fights with an octopus fish-man called Hatchan. Seemingly defeated with one strike, Sanji looks over to Zoro. He is punched by a ray fish-man named Kuroobi as he was distracted by Zoro.

Some time later in the battle, after Zoro has defeated Hatchan, Kuroobi attempts to finish off Zoro. Sanji, who was also seemingly defeated, comes to Zoro's rescue and kicks Kuroobi away.

After both Hatchan and Kuroobi seem to be defeated, Arlong himself enters the scene. Zoro tells Sanji that he can give him 30 seconds to grab Luffy. Hatchan, who was apparently not defeated, dives after Sanji. Zoro doesn't seemed to be worried, as Hatchan is covered in wounds and moving will reopen them. Sure enough, Hatchan's wounds reopen and Sanji makes a successful rescue.

In the aftermath, Sanji and Zoro can be seen sitting across from each other in an alley as Cocoyashi village celebrates the downfall of Arlong. They make small talk about each others wounds.

Reverse Mountain Arc
When the crew meets Crocus, Sanji attempts to communicate with him. Crocus ignores Sanji, causing him to get frustrated. Zoro calms him down and talks to Crocus instead.

Fanon
ZoSan is the one of the most popular ships in the One Piece fandom and at the same time the most popular slash ship in the fandom. It's a rival ship to SaNa. A big part of the One Piece fandom that enjoys Zoro x Sanji pairing usually ships ZoSan alongside with LuNa and Frabin.

Fandom
FAN FICTION

TUMBLR

PIXIV
 * Sanji/Zoro on Pixiv