There are several characters throughout the game that have lists of wanted demons for Ammy to hunt down. Each demon on the list can only be found at night, and they are in a different spot than the normal demon scrolls during the day, making them easy to find. Each demon on the list is also only in the area corresponding to the list. After you defeat each demon on the list, go back to the person who gave you the list and they will give you gold dust.
Wanted lists are available in there areas:
Shinshu Field: Talk to the priest in the shrine near the Moon Cave.
Kusa Village: Talk to the girl in the room of the inn at night. First you must head butt the bathroom door, leave the inn and return. She will be in her room.
Sei-An City, Commoner's Quarter: After you clear the mist, talk to a man walking near the gate to the Aristocrat Quarter. He'll brag about a list of demons he is going to defeat. Go into the restaurant at night and he will be drunk and you can take the list from him. Warning! If you talk to him after you've taken the list but have yet to defeat all the demons on it, he will chase and attack you!
Kamui: Talk to the man in the hut near the frozen pond.