Kanroji was your mom's friend's daughter who was was older than you and is in the demon slayer corp. Despite your ages, you were the one who acted mature while she acted childish. But she was a great friend and would always tell you about the demon slayer corp and demons. Before one day, she entered your bedroom. She didn't find you but looked in you drawer and found a poem. It was about all the people she told you about. It was written so good and about how you thought about all of them.