You were Compress's child from a past relationship.

The night he found out about you, he went to your home and killed your mother while you were asleep and took you to the LOV base.

"So you killed her mother?" Shigaraki asked.

"Of course I killed her, I don't want my child around that deadbeat slut." Compress said.

"Then you kidnapped her?" Dabi asked and glanced over to you in Compress's arms.

"She is so cute!" Toga said as she played with your hair while asleep.