Coming back here after thinking about northeastern Luffy/ASL brothers in Brazil just to write more headcanons. (This will probably have part 2 with other characters)
I am Brazilian too, so that's my silly therapy👆thank you Oda for giving us the most cutest, funniest, well made Brazilian character in anime (to my knowing) .
1- Luffy is probably northeastern or from the north. I think he's either from Manaus (north), Itacaré or Aracati (northeast).
2- Garp is probably from Paraná (south). He got enlisted in the army in his youth and is now retired, but he's one of these old men that has the most fascinating and crazy life's backstory. He tends to spend his free time in a small bar drinking a cool Skol (though he says it tastes bad) and likes a good chopp of Brahma. He doesn't hate Amstel, but thinks it has a weird taste. (He likes whisky too). Garp has played Jogo do Bicho but never got caught (jogo do bicho is illegal in Brazil as well as casinos and gambling games). He has bet on the donkey and lost. Also, Garp plays snooker at the bar and he's pretty good.
Note: I don't know if I hc Garp as retired (INSS fears him) or assign him a job now...
3- Ace is Portuguese (this is actually canon lolz) but he grew up in Brazil with Luffy and Sabo. Ace moved here with his mother when he was 6, because she had a terminal illness + was being hunted by the marines/military and knew she wouldn't live longer, so she came here to leave him with a person of trust: Dadan.
Dadan was a very close and intimate friend of his mother, they met when Rouge came on a trip after a heartbreak. They became friends in these long months of Rouge's stay. Dadan visited Portugal once too for studies 5 years later and they ended up seeing each other again, but Rouge was already pregnant and married to Roger. After Roger's death, Rouge left Portugal. Now, Ace was entrusted to be under her care. Dadan knows Garp for years and she was paid to take care of Luffy plenty of times since Garp not only rather be at the bar, but he sometimes gets busy. That's how Ace and Luffy met to be honest. (I wanted to hc them as blood brothers, but not this time).
Note: Dadan is a northeast woman from Maranhão. (I thought of Aracaju—Sergipe too) She also knows 3 languages (pt-br, English and French), coursed languages in university and started administration.
4- Dadan was quite anxious with the boys at first, because they would fight a lot and keep biting or pinching each other. Once she found them listening to Vodca ou Água de Coco by accident and went bananas turning the music off (it's not for kids! Obviously), they laughed a lot at her and it became their inside joke, which got them a little closer. She taught them how to play marbles too.
5- Ace and Luffy used to really like to fly a kite. They started getting closer by doing this. (They bonded a lot😭💓) and I think Luffy kind of likes football, but he knows nothing about it, he just pretends to know because Ace had a phase in which he really liked football around his 12's. They would play just for fun and with other kids randomly, but they're not really a fan of it (though they go crazy when it's the World Cup!)
6- Sabo moved to Brazil when he was 8. He still has an accent (which is beautiful!) but knows Portuguese really well. He studies very hard and his family is very busy, so he's often by himself. He met Ace and Luffy in the most random and awkward way possible and they clicked very fast! Sabo didn't live far away from them, so they would meet very often. Also, Sabo just invited himself to "live" in Dadan's house too since, again, his family were mostly busy with work and he was alone often. Then she was their "mother figure", she acted like one. Which means...if you're Brazilian or familiar to latina moms, you'll get it😭
7- Sabo learned French because he got inspired by Dadan. He also had a goal to learn +8 languages (he failed though. He got distracted by being stupid with his brothers for a while).
8- Luffy knows spanish. He learned the language because one of Garp's friends was chilean. At the time, Dadan was busy with work and university, so Luffy would spend some time at the bar, playing marbles and being taught how to play snooker too. Each of these days, the owner would give him juice and coxinhas, or crackers...perhaps, if he behaved well, pastel. To be honest, Luffy quite likes palm hearts pastel, but he's not going to admit it.
9- Ace hates palm hearts pastel. Sabo doesn't eat it. He loves carrot cake. I think they share the taste of X-Caboquinho and Tucumã. (And homemade carrot cake). Paçoca de carne + baião de dois is probably the favorite of Ace and Luffy. Also, Ace loves açaí, but he kind of doesn't like bananas in it...Luffy likes to put bananas and he doesn't care.
10- Ace and Luffy wear the Brazil shirt for no reason (can't explain this. Here in Brazil some guys do this lol). Sabo goes along with them. I think Sabo likes the Olympics by the way.
11- They used to play the aqua girl and fire boy game a lot‼️
12- Luffy ate his devil fruit at that time in the bar too. Shanks and his crew were roaming around the city for a while stocking up food etc. Shanks had the gum gum fruit in his bag. While he was playing snooker with the other men at the bar, Luffy (a kid) found the bag open and ate the fruit. It was chaos that day. I feel like Ace ate his fruit accidentally too.
13- Some people call Luffy Macaquinho (Little Monkey) because of his surname and he got used to it tbh. Ace is known as Isqueiro (Lighter) and when the song Atoladinha (Enterradinha) came out, Luffy and Sabo annoyed the hell out of the dude with the lyrics. They started calling him Bola de Fogo (fire ball 😭 as an inside joke). Sabo is known as Alemão (literally German. No, he's not German. People here give weird nicknames.)
Note: Atoladinha's lyrics are about a girl getting a call from a fire ball (?) and he says how the heat is too much and that he's going to drop a hit at the beach. Quite weird to explain lmaoo
14- I want to believe they live next to a river just to bond while swimming, fishing or riding a boat. Honestly, I might be stupid cuz I don't really know if they can swim on rivers after eating the devil fruits, but I'll say they can because it sounds very cute🥺 (like, I think it's just the sea that's a problem, right?)
15- Luffy and Ace are very eclectic in terms of music. I think Sabo has more preferences...I can see them listening to É o Tchan and memorizing the dance ngl
16- Luffy's dad is northeastern, his mother may be too. Not sure about this one, gonna elaborate further.
17- Garp is not only a quite crazy grandpa, but he taught the boys methods to cheat on school tests, random magic coin tricks, snooker (obviously), how to properly catch fishes etc.
18- They didn't have health insurance, so when Sabo broke his arm trying to skate once, he got taken to SUS (public free health system. You don't have to pay for anything.) and it was quite messy.
These are the ones for today, I tried to think of more but it's very late already. Thank you for reading!