You can start The Butterfly Collector quest by hearing a rumor from an NPC (a vendor or someone you rescue during a random event). This will lead you to Katano, which is located west of Katano Castle ...
As part of "The Butterfly Collector" quest given by the Gamekeeper in Assassin's Creed Shadows, you'll be tasked with tracking down ten origami butterflies scattered around the Osaka region. This is ...