Sword Master's Hat is a hat that unlocks when you upgrade Ronin Attire to level II. It is added automatically, so there is nothing to find in the world.
Upgrade Ronin Attire to level II. The hat shows up in the Helmet slot right after.
You can pair it with any armor, not just Ronin Attire.
Ashen Straw Hat
Ashen Straw Hat is a hat that unlocks when you upgrade Ronin Attire to level IV. It is added automatically, so there is nothing to find in the world.
Betrayer's Hat
Betrayer's Hat is a straw hat you get by finishing "Shadow of the Samurai" in Jin's Journey. It is a story reward, so you cannot buy it.
Bloodstained Betrayer's Hat
Bloodstained Betrayer's Hat is a New Game+ hat sold by Baku the Voiceless for 5 Ghost flowers. It is not available in a first playthrough.
Bone White Straw Hat
Bone White Straw Hat is a New Game+ hat sold by Baku the Voiceless for 5 Ghost flowers. It is not available in a first playthrough.