Y/n Hoshino or more commonly called Y/n who was known as Sarina Tendouji in her previous life is the daughter to the star Hashira, Ai Hoshino and the younger twin sister to her older twin Brother Aquamarine/Aqua Hoshino. Being neglected by her parents in her previous life and being a fan of Ai and wanting to join the demon slayer corps enjoying her new life but that all changed when her mother was murdered. Afterward she was determined to fulfill her mother's dream, she became a demon slayer along with her friends and befriended a demon on the way.