It makes perfect sense that Kozaburo could have been friends with Dragon if he was the rebellious type too. If Tashigi is connected by blood to the Shimotsuki clan there is an irony that she is possibly the granddaughter of a pirate.
Its interesting that Kuina and Kozaburo were very close.
Its interesting that Kuina and Kozaburo were very close.
There's still that interview with Oda where he was asked if there was a connection between Koshiro and the Revolutionary.