What props can four NPCs exchange for the death diary?
Every time an NPC knocks on the door for the first time, he will ask you for something. Give it to half a heart. If you don't give it, it's zero. Unless what he wants is worthless, it is just some water, materials, potatoes and meat. When NPC visits, they will appear on the map. At this time, you can send something to be friendly and unlock it.