Zoro is the son of Roronoa Arashi, who married a woman from East Blue.
Zoro’s father, Arashi, is the son of Shimotsuki Furiko and Roronoa Pinzoro, who were both natives of Wano Country, the land of the samurai.
Zoro’s grandmother, Furiko, is the elder sister of Shimotsuki Ushimaru, the former Daimyo of Ringo in Wano, who died fighting Kaido’s invasion.
Zoro’s grandfather, Pinzoro, is a descendant of Shimotsuki Kouzaburo, a legendary swordsmith who forged Enma, one of the swords of the former Shogun of Wano, Kozuki Oden.
Zoro’s ancestor, Kouzaburo, left Wano 55 years ago with a group of 25 people and settled in East Blue, where he founded Shimotsuki Village, the place where Zoro grew up and learned swordsmanship.
Zoro’s distant ancestor, Shimotsuki Ryuma, was a legendary samurai who was known as the “God of the Blade” and who once slayed a dragon in Wano. Zoro met Ryuma’s corpse in Thriller Bark, where he inherited his sword, Shusui, which he later returned to his grave in Wano.