Journey into Night is a dye for Traveler's Attire. It costs 10 flowers at the Black Dye Merchant. Like every dye it only changes colours.
The Black Dye Merchant hides in a dark cave in the bamboo forest east of Kawamata Village, in Kushi prefecture, Toyotama. You have to find him by exploring, and more of his stock opens as the story goes on.
Once unlocked it shows up as a colour option for Traveler's Attire, so you need that outfit to use it.
Akashima Bamboo Strike
The Akashima Bamboo Strike is a sword-timing challenge near Fort Ito in Toyotama. Cut through all the bamboo with the right buttons and it counts toward raising your maximum Resolve.
Akashima Haiku
The Akashima Haiku is a poem spot where the river meets the sea, just south of Old Kanazawa Marsh in Toyotama. Sit down, pick three lines and you earn the Headband of Uncertainty.
Akashima Lighthouse
Akashima Lighthouse is one of the 10 lighthouses Jin can relight, at Fort Ito, Toyotama. Lighting the fire gives a minor boost to your Legend.
Amber Assassin
Amber Assassin is a dye for Ronin Attire. It costs 10 flowers at the Toyotama merchants. Like every dye it only changes colours.