The Dark Kind came to the world as conquerors. They failed. Now they are odd neighbors.
HeartKind bands are a way for Dark Kind (or any Deamonic/Monsterous kind) to show that people have nothing to fear from them.
As part of The Pact that ended the Six Stars Demon Wars, various places were given over to the Dark Kind. This is their neighborhood in the city.
A young girl with a dirty face and tattered dress stands near the town market offering to sell the PCs freshly cut flowers. They are only a single copper a piece, and smell nice. Perhaps the PCs will be generous with their wealth, or they will not. Great for paranoid parties.