LOST AND FOUND

Luffy was young when they first met, they're both a part of the crew of 2 of the 4 emperors of the sea.  One is just a 5-year-old girl while the other is 17 years old boy. Everything is the same every time the Red Hair Pirates and Whitebeard Pirates cross path, having booze, partying, sparring, and sharing stories until 4 years later the young girl went missing