You were the twin sister of Muichiro and Yuichiro but after Yuichiro was killed by a demon, your big brother Muichiro became a Demon Slayer. You wanted to be one too but he didn't let you, he was afraid of losing you too.

One morning you were about to go gather some herbs to make lunch for Muichiro but he stopped you. You can't go alone in the forest, it's dangerous. He spoke, his hand on your shoulder.