For years there have been several hints that Zoro is from Wano, and I am here to tell you my theory on how he and Wano might be connected.
Want do we know so far:
1- Zoro is currently 21 years old
2- Kurozumi Orochi and Kaido killed Oden and took over Wano 20 year ago
3- Ryuma’s Grave was robbed 23 years ago
4- When Ryuma was alive, he had a striking resemblance to Zoro.
5- When Momonosuke shouted “Snatch!” (a shout that he learned from Zoro), Kiku told him that it came from an ancient dialect and told him not to say it; implying the word and its origins are taboo in Wano.
6- Back when the Kozuki Family ruled over Wano Country, Yasu served as the daimyo of Hakumai. His real name is Shimotsuki Yasuie.
Shimotsuki is also the name of the village Zoro grew up in!
7- Koushirou (Zoro’s first sensei) came from Wano based on fact that Hyougoro told Luffy the same thing Koushirou told Zoro during his training. In the image below you can also notice the symbol of cross swords. The same symbol we already saw on Koshiro’s clothes!
8- Tenguyama Hitetsu has been remaining in hiding stayed in the ruins of Amigasa village in order to wait for someone.
9- Gyukimaru (The Warrior Monk) was adamant about Ryuma and determined to keep Zoro away from the burial
Zoro is a actually the descendant and heir of the same clan that Ryuma came from.
The Clan was once respected and renowned in Wano for hundreds of years, but when Ryuma’s grave was robbed 23 years ago the clan that sworn to protect it was shamed throughout Wano and considered taboo to talk about. Orochi found the shamed clans’ leader (Zoro’s father) and his retainers Koushirou, Hitetsu, Gyukimaru taking refuge in Amigasa village 20 years ago and sought out to recruit them to help take down Oden, but they refused because they still wanted to stand by their honor and not kill Oden. The enraged Orochi decided to kill them for turning him down; as a result Zoro’s father was killed leaving behind Zoro (who would be a one year old baby at this point) and the retainers. In order to protect Zoro, Koushirou decided to leave Wano promising his fellow retainers that he would return once the reign of Orochi was over. Koushirou fled and hid in the East Blue to where he looked after Zoro at a distance and train him as a swordsman.
*Theory by NationalStrategy