Eiichiro Oda has carefully created the characters of One Piece, and some of the characters are directly connected but are either aware of that or unaware. Such two characters are Yasopp and Usopp. There are plenty of similarities between the God Usopp of the Straw Hat pirates led by the emperor of the sea, Monkey D. Luffy, and Yasopp, the infamous sniper from the emperor of the sea Shanks' Red Hair pirates. They both look somewhat similar and are snipers of their respective pirate crews.
Not just that they both even hail from the same place, Syrup Village, which is in the East Blue. Yasopp and Usopp share these more than necessary similarities because of a big connection between them, which is of a son and a father. Yasopp is indeed Usopp's father, not many of the fans knew this information for sure before it was cleared more and more by Oda as the story of One Piece moved forward. Yasopp and Usopp both are strong pirates in their own right.
Yasopp's Backstory
Yasopp was an ordinary citizen of the Syrup village, he married a woman named Bachina, eventually, and they had a son named Usopp who after growing up came to be a part of Luffy's pirate crew. In moments of happiness, Yasopp always dreamt of living the rest of his life as a pirate sailing the seas, but he didn't have the motivation to actualize his dream. Afterward, he was recruited by the 'Red Hair' Shanks who was starting his journey as a pirate back then. His wife Bachina did not hold him back and instead asked him to fulfill his dreams regardless of the fact that she was going through a chronic illness.
He left his village after joining Shanks' crew and became the sniper of Red Hair pirates. He even met Luffy (who would later become his son Usopp's captain) when the latter was just a kid in the Foosha village. He told Luffy stories about his son Usopp and wished to see him again in the future.
Usopp's Relationship With His Father
Yasopp leaving his home, wife Bachina, and his son Usopp (while he was still a child) make clear that Yasopp is not certainly the best father out there despite all this he loves Usopp and is proud of him for the latter making a name for himself in the pirate world. He was joyous to see the wanted posters with bounties of the Straw Hat pirates including his son Usopp when Dracule Mihawk visited his crew during the Loguetown arc with the wanted posters. Even after the time skip, he could be seen laughing happily checking out the newspaper that included the increased bounties of Straw Hat Pirates after the Dressrosa saga.
Usopp being a jolly and kind-hearted person does not hold any grudges against him instead, he is quite proud of his old man who was also his inspiration for becoming a pirate in the very first place. Even though he does not know much about his father, Usopp takes pride in the fact that his father is in Shanks' pirate crew. Usopp has inherited his father's talents like sniping skills and incredible marksmanship. Usopp loves and highly respects his father, Yasopp.
When Will They Reunite?
It is not sure when the two will reunite, but they are bound to crossroads when Shanks will reunite with Luffy at some point in the future. However, at the end of the Wano arc, Shanks and his crew were seen in a sea near Wano, and they were seen discussing the news of Luffy and his allies defeating Kaido and Big Mom. They could be seen talking to Shanks about Luffy becoming an emperor of the sea now, and it is the right time for them to meet Luffy and his crew.
Amidst this Yasopp was nervous about meeting Luffy and his crew as he is not mentally ready to meet Usopp after all these years of being absent from the latter's life. This shows his insecurity as a father who was not there for Usopp during his early years for he had to pursue his life goal of becoming a pirate. But Usopp is not the kind of person to have any hard feelings for his father if anything he understands Yasopp's situation the latter had to leave home to fulfill his dream and Usopp is aware that pirate life sometimes asks for big sacrifices.
There is a high probability of the two (Usopp and Yasopp) coming across each other at some point later in the story of One Piece in the future. It would be one great sight to behold when these two great snipers are finally reunited. Although, there are chances that they might have to fight each other if Straw Hat pirates have to go against Red Hair pirates in a battle at some point in the future. Regardless, fans want the sniper father-son duo to meet each other, amend their relationship and tell each other about all the adventures they experienced while sailing as a pirate.