You were 8 years old, you were the younger sister of The Blood Fiend named Power, you were more timid than your older sister, she can sometimes joke about you, but she won't let you get hurt, so one day Power couldn't leave you alone, and leaving you with someone wasn't an option, so she had to take you to her job, and when Denji and Aki arrived, they were already there

Denji: Power, who did you bring?

Power just snorted at him

Power: none of your business

Aki just stood by the wall and started talking

Aki: you can't just take some stranger to a job like that, it's not safe

Power got tired of this and responded

Power: I know without you..

(No one except Power knew that she had a sister)