More than 50 years ago, Kozaburo illegally left Wano Country.
Around 25 or so years ago Izo left Wano to join the Whitebeard Pirates, and just recently Momonosuke, Kinemon, Kanjuro and Raizo left Wano for a journey to Zou.
What I’m trying to establish is that people leaving Wano despite its closed borders policies doesn’t seem to be a rarity. In fact, I think there are plenty of Wano natives out there and Shiryu is just one of them.
1. Kiri-sute gomen – The right to strike, an old feudalistic samurai expression
Often translated to “license to kill”. When Shiryu was first introduced and released from his prison cell, he immediately cut down the guards to test his meito with the excuse of , or a samurai’s honour. Back in the day, samurai had the right to kill any lower class citizens who they felt had compromised their honour. It’s similar to the practice of the shady Wano magistrate who killed random people in the streets.
2. Raiu – Thunderstorm, Shiryu’s Cursed Meito
With its size, square hand guard and bloodsplattered pattern, Raiu doesn’t seem like your average meito. I think it’s a cursed one that thirsts for blood and is one of the 21 great grade swords, among the likes of Enma, Shusui and Wado Ichimonji. He’s definitely taking good care of it, just like Zoro and the Monk Gorosei.
It’s also interesting to note that Raiu’s name (雷雨) includes the kanji for rain just like Shiryu of the Rain’s epithet (雨のシリュウ) . Why’s that important? Well, it isn’t but it’s a nice side fact and instantly makes me think of Wano’s northern regions for some reason.
3. Roronoa Zoro vs Shimotsuki Shiryu – A very personal Fight
What I think is the case is that Shiryu is a fallen, cast-out or simply evil heir of the Shimotsuki clan, because that’s exactly the theme of the Blackbeard Pirates. It would also give a completely new dimension to his possible role as Zoro’s nemesis, someone who may have a relationship with Koushiro, the Shimotsuki Village and maybe even Ryuma, and someone who has brought shame to the Shimotsuki line. The anthithesis to the samurai code; an honourless evil ronin from the lands of Wano.
*Theory by Admiral Ryokugyu