The past:

When Hisako was 7, she went to the playground and wanted to play with kids. She try her best to fit in but kids didn't want to play with her as she was sad hugging her penguin plush when she offered to play with a group of kids. She happily agreed and try to play with them but she accidentally trigger her icy magic and harm a kid. She try to apologize and help but the kids were afraid of her and call her a monster while she took there upset and felt like a curse.