Roronoa Zoro's lineage and family history have been a talking point among One Piece fans for years. The green-haired swordsman's Japanese origins seem to imply that answers might be found in the Wano, a land loosely based on feudal Japan where samurai still reign. In fact, Oda may have just revealed the answers everyone has been looking for by means of a flashback.
Under Kozuki Oden's Shogunate, Shimotsuki Ushimaru was the Daimyo of Ringo in Wano. After Oden's death, he lost his position and was put in prison by Kaido. Since Ushimaru's debut in the manga, there has been a theory going around regarding his relationship with the second-in-command of the Straw Hat crew.
Fans think Shimotsuki Ushimaru is the real father of Roronoa Zoro in One Piece
Fans are familiar with Eichiro Oda's foreshadowing of important events and connections in the One Piece story, and this fact has caused many a reader to analyze various aspects of the One Piece narrative in an effort to dig out more tidbits of trivia regarding the Straw Hat crew. Vinsmoke Sanji's origins have been the focal point of the Wholecake Island Arc, and as such, the Straw Hat cook has long surpassed his rival, at least as far as the backstory is concerned.
With other members of the Monster Trio being revealed as descendants of important figures, it is no wonder that people expect the same for Zoro. Despite his continued importance in the story, Zoro has received the short end of the stick when it comes to his past. Fans know that his drive to get stronger is borne of a desire to honor his shared childhood dreams with Kuina, who died while they were both children.
However, Oda has been strangely secretive while revealing anything else, leading to speculations about his origin. Zoro's birth in Shimotsuki village is regarded as the primary hint about him being the son of Shimotsuki Ushimaru. Hyogoro the Flower even admits this in Wano, commenting on Zoro's uncanny resemblance to the former Daimyo, and fans are tempted to agree.
Zoro also has the same sword style as a legendary samurai, leading to the narrative about him originally hailing from the Land of Wano. The story has long foreshadowed a connection between Zoro and the ancient samurai Ryouma, who also happened to be Shimotsuki Ushimaru's ancestor.
Shimotsuki Ushimaru is NOT Zoro's father, Oda confirms
Despite the fan theories and brilliant speculations, however, Oda confirmed in the SBS that Ushimaru is not Zoro's father. He does note the similarity between the two characters and does not entirely debunk the idea of Ushimaru and Zoro being related in One Piece. In fact, fans have reason to believe that Ushimaru is Zoro's grand-uncle instead, as the younger brother of his grandmother.
Whether or not more information is revealed regarding Zoro's ancestry, the narrative does not really require him to be Ushimaru's physical descendant. One Piece as a narrative revolves more around the inherited will or a desire for the continuance of a departed soul's dream through the actions of the living. This is evident in Luffy being Roger's spiritual successor, even though Ace is his son.
Fans have been slightly disappointed by this revelation, but several of them are unwilling to believe the new information, choosing instead to think that Oda-sensei is intentionally misleading this. Yet others have started locating new clues to Zoro's ancestry, while others are waiting eagerly for the mangaka to draw Ushimaru's bloodline.
Fans can read One Piece on Viz Manga or Shueisha's Shonen Jump+, and stream the anime episodes on Crunchyroll and Netflix.