"I wonder what death feels like." Y/n Tsugikuni is the only daughter of the strongest demon slayer: Yorrichi Tsugikuni. Y/n had a very big fear of death. Just like her uncle Michikatsu Tsugikuni. She was trained to be the successor of Breathe of the Sun. She became a Demon Slayer. She watched as her father got killed by her own uncle. With that the fear of death grew. Her uncle convinced her to become a demon with him. Learning Breathe of the Moon as well as Mastering Breathe of the Sun. Earning her the spot of Upper Moon 1, sharing it with her uncle.