Zosan

One of Sanji's most easily noticeable characteristics is the calm, cool, and collected way in which he behaves. He tends to speak in a very composed manner, even in dire situations, and rarely acts without thinking. His behavior in a number of ways can be compared to that of a secret agent. This is amplified by the fact that he tends to wear a suit, often enjoys a smoke, and in the anime they tend to play soft music with jazz tones when he speaks. He often makes comical exceptions, such as when in the presence of beautiful women, or when angered by a crew member. Like Zoro, he is more perceptive than he appears, and often tells people what they need to hear, rather than what they want. Because of this, he is seen as one of the more hardened members of the crew and can often be as scary as Zoro at times.

Unlike Zoro, however, he is not afraid to show his emotions when the moment calls for it, and is entirely capable of yelling or losing his temper, which results in Sanji's short fuse and subsequent beatings from most villains ( and Luffy). Although Sanji appears to be one of the more hardened members of the crew, he is not opposed to acting stupidly on certain occasions, such as dancing with the more immature members of the crew (Luffy, Usopp, Chopper, and Brook), or acting childishly excited in certain situations. (like when you first visited Skypiea).

He is very amorous, constantly flirting with any attractive woman he sees, earning him the nickname "ero-cook". In fact, he claimed that Nami was 98.72% of the reason he joined Luffy's crew in the first place. Since then, and a while later, returning to the Sabaody Aquipelago after his two years on Momoiro Island, Sanji has become even more perverted, acting differently when he as much as the thought of beautiful women (mainly his crewmates, Nami and Robin ) and acting strangely when he got around "real" women, causing others to question her about whether he was really okay or not. He is also known to display jealousy towards others when their luck with women seems better than his. Even though he is a pirate, Sanji has a policy of never attacking women.

Although they can sometimes behave casually and calmly towards each other, Sanji very often gets into physical and verbal fights with Zoro (who he refers to as "marimo" or "mosshead" because of his green hair) throughout his differences, and is nicknamed Ero-Cook and Prince of the Okama Kingdom, among other things, by Zoro. Despite their rivalry, the two respect each other's abilities. During the Little Garden Arc, Sanji and Zoro inadvertently took on the same dinosaur meat hunting challenge that the two legendary giants Dorry and Broggy started 100 years ago. From there, and the inhuman amount of power the two possess, their rivalry is akin to legendary status. However, although he spends a lot of time arguing or competing with Zoro, Sanji never tries to diminish Zoro's abilities and even during those rare occasions when Zoro claims to be greater than everyone else. He also tried to stop Zoro from sacrificing himself to Kuma to save everyone else by letting him take his life (although Zoro knocked him out before he could do so). After waking up to find Zoro, he showed great concern about what might have happened to him. Despite their rivalry, which can sometimes impede their effectiveness during battle, once the two agree to work together, they become an almost unstoppable force, as they instantly turn the tables on the monsters Groggy.