ASTRO/6 siblings

Sia is the main character, she's adopted, but Astro adopted her and she ends up living with 6 siblings. But the 6 siblings are bullies, and Sia used to be a bully too, but because of some trauma, she's scared of him. When she gets angry, she shows herself as a bully. And Astro likes his older sister, so he can't be a man and always hangs around her. It's a story about siblings, so it's really messy haha