He finds Luffy on his own. The rubber boy's sitting on a curb watching a man in the street juggle fire, and after a moment, Sanji sits next to him.
Neither of them speak for a long minute, and finally Luffy says, "I'm not a normal nineteen year old."
Sanji lights a cigarette. "Doesn't matter. I shouldn't have said that."
Luffy's not looking at him, so Sanji's only got a profile-view of the boy when he speaks a few minutes later. "It's okay if you don't like me." Sanji only very barely manages not to flinch, but it's a close call. "You don't like Zoro, but you're still nakama, you know? So it's okay if it's like that with me, too. As long as you always look out for everyone else, it's okay. Cause I'm the captain, so I can look after myself."
Sanji reaches for the boy beside him but his hand stalls halfway through- he doesn't know how to do this- and it falls back to his side.
"But I don't want it to be like that. 'Cause I love you all so much."
Sanji stands up, shoves some guy out of the way, and hauls Luffy up so sharply he drops his hat. And when Luffy's on his feet, Sanji leans in so Luffy has nowhere to look but him.
I waited those two years, just like everyone else, he wants to shout. I trained and worked and hauled ass to be good enough to stand by you when we all came back together. I was just some chef from East Blue when I met you, and now I'm a wanted man, I'm Black Leg Sanji, I'm the one who's going to find All Blue, and you- you're my captain. You, and that damned Straw Hat pirate flag, you're my home.
But he doesn't.
He just says, "It's not like that."
Because, no matter what, Luffy has a faith in his friends that defies everything; after a moment, the rubber boy is smiling at him, and Sanji thinks his heart will always hurt a little when he does.
He may not be like Zoro, or Usopp and Chopper, or Brook, who can play with Luffy for hours and hours; he isn't like Franky or Robin or Nami, who can entertain the captain with stories or books or maps.
But Luffy doesn't choose friends with the intent to change them; and Luffy picked him out of a wide blue sea, and smiles at him in the mornings over pancakes and chocolate milk, and Sanji knows he doesn't need to be like anyone else.
"And don't say any dumb shit about looking out for yourself just cause you're the captain. I'm still gonna look out for your sorry ass, whether you like it or not."
Luffy picks up his hat, the smile stretching into a grin. "And it doesn't matter that I'm not a normal nineteen old?"
You changed everything, don't you get it? You're not normal, but you're our normal. You're usual and familiar and always, a weather pattern, a season. You're impossible, but you changed our whole world to match, made everything in it as impossible as you.
You're the laws of the universe. The sun at the center of a galaxy, and we're the spaces between your stars.