Never

Aiko is just like any other ghoul, just trying to get through these tough times. Being the daughter of the owl, she's not exactly favored by the ghoul community. Due to her small frame and the fact that she's female, the others decided that she was an easy target.
Despite this all who cross her are immediately put in their place. Though she's strong, she's finally pushed to her limit, and that's when our story begins.