Sanji, also known as Black leg, is a pirate and a cook of Strawhat Pirates led by Monkey D. Luffy. Sanji joined to the crew after Baratie arc as the fourth member. Sanji always has a black suit with a tie and a long-sleeved, buttoned shirt on himself. What’s interesting is that his outfit changes more often compared to other Straw Hats.
#1 Sanji’s name can mean “three o’clock” or “three o’clock snack”. This points to a wider theme in Sanji’s character, revolving around the number 3.
Sanji is the third son of the Vinsmoke Family. Sanji is also often considered the third-strongest member of the Straw Hat Pirates. Sanji usually fights the third strongest member of the villain group the Straw Hats face during the story arcs. The exceptions to this rule are in Punk Hazard and Dressrosa.
#2 Sanji is the only Straw Hat shown so far to have biological siblings.
Nojiko is Nami’s adopted sister, while Ace and Sabo are Luffy’s sworn brothers. Ironically while Nami and Luffy adore their siblings, Sanji and his brothers actively despise each other. Despite that, Sanji’s relationship with his sister is very good, since she was the one who helped him escape.
#3 Sanji is actually modeled after Steve Buscemi.
According to Eiichiro Oda, people often speculate that Sanji’s character is modeled after Leonardo DiCaprio, but he is actually modeled after Steve Buscemi as he appeared in Reservoir Dogs.
#4 In One Piece: Burning Blood, Sanji has a special attack “I won’t kick a woman, even if it means my death!”
That causes all his attacks (including his special and ultimate moves) to comically change into hearts and causes his health meter’s portrait and the face on character model to change to his “heart eyes” face, when fighting female characters (as well as Bon Clay (Clone) who is considered a female character in his DLC “Nami Mode” form). Unlike the Pirate Warriors series, Sanji can still attack female characters and “hearts” he produces can cause minor damage to female opponents. However, Sanji is still weak against female characters.
#5 Sanji received Swordsmen training when he was a child from his father.
This is ironic considering Sanji couldn’t care less for swordsmen like Roronoa Zoro, though it’s likely this training evolved into Sanji’s skill with kitchen knives. Also, he stated that he would never fight using his hands which are only meant for cooking.