white day ghost's x female reader

Your name is Y/N-Hee, Kyung Hee's younger sister. You were able to get a job, became very popular, made a lot of money, and made your family wealthy, but you couldn't get over the death of your older sister, who you lost when you were four years old.but you never got over your death of your older sister you lost her when you were only four.but what happens when you stay in your school after hours?