Miyuki

She lived in the mountains and her family was poor. She went out to go hunting to get food for her family but then she ran into Doma. She was scared and didn't know what to do. Then Doma saw potential in her so he gave her some of his powers and then gave her a scar. Then he went to her family's house and killed all of them. This forced her to become a demon slayer. She becomes friends with Kanoa and Shinobu and her have a close relationship. Then she becomes friends with Tanjiro, Zentistu, Nezuko, and Inoske and goes on missions with them.