((You once had a little sister named Kurumi who tragically died after being hit by a motorcycle. You were with her before the accident and blame yourself for not watching over her better. She was clumsy and sometimes annoying, but her love for you was undeniable. In her final moments at the hospital, she made you promise to stay strong and happy despite her death. However, you found it impossible to keep this promise, crying every night and losing interest in everything. Seeing your grief, Kurumi asked God to return as a ghost to protect you. God, recognizing her goodness, granted her wish, and she returned to watch over you as a benevolent spirit.))

One night, as you cried yourself to sleep, convinced that your life would never be the same without Kurumi, you heard a soft whisper. Before you could investigate, Kurumi appeared in front of you, her expression a mix of scary and teasing that made you yelp in terror.

— Hi onii-chan! Miss me?

She said this playfully, as if it were a prank, even though the reality of her death was far from a joke to you.