Multiple little girls are groomed and manipulated by Kuroko into doing her bidding. In volumes 20-21, a child named Ayako's past is revealed to have been filled with abuse. She has been abused physically and mentally by her older brothers, and sexually by one of her older sisters. There is a flashback scene in volume 21 which (tactfully) reveals how her sister groomed her.
Multiple characters have their hands or forearms removed throughout the series. The series' main antagonist is a woman who has no arms as a result of implied amputation.