Okay but - Rouge is actually Sabo’s mom, and Gol is Ace’s dad, but they’re really close and he always has to hug Ace after he has a rough scene talking bad about himself or his dad.
Crocodile got Luffy a bucket of chicken wings with a “Sorry I stabbed you” after the Alabasta arc, and Sterry and Koala are siblings.
Shanks hate like green cause he’s spent almost the entire show with a green screen sock on his arm. Of course the cast gifts him a whole bunch of stuff that color and he laughs about it (doesn’t keep it, but he’s nice about it).
Kid’s in make up for like three hours every morning cause aside from freckles his skin’s flawless. He’s a goofball and a bit of a prankster, his natural voice is smooth but learning how to death metal growl is why he’s able to do his Kid voice so consistently.
Killer grew out his hair for the role and was only wearing a wig before the time skip. There’s some filler in it to make it more volumetric, but it’s still mostly him.
Sanji’s hair is black and Benn Beckman is his Uncle. He convinced Sanji to try out for the role since his hobby was cooking.
Franky is Franky. He and Ivan own a few clubs together and the cast goes to the one by the studios to unwind after shoots.
Bonney is also Reiju, and is married to Yonji. He wasn’t originally going to be in the series but him and his two brothers kind of tripped into the roles by accident.
Doflamingo is one of the Producers and only put his name in the hat for his role as a bet with his brother Rosi and their nephew Law, because Doffy knew Law would be a good fit for the Heart Pirates.
Pops’ is actually Marco’s dad, and a retired body builder. Marco told him he’d be surrounded by pretty nurses for most of the scenes, but he wasn’t convinced until he read about the Marineford scenes and saw he’d get to be in a cool fight.
Teach is Usopp’s uncle and Benihana’s (I think that’s her name) brother. Yasopp wasn’t related, but Beni was divorced by the time the show started and the two hit it off. Unlike his show counterpart he spends just about free moment he has with his now wife.
Pops died in real life just after Marineford finished filming. Marco needed a few takes to get through the scenes with Shanks in front of the tombstones. (I can’t just let my man have peace even in an AU I guess T-T)