Ai grew up believing her father worked abroad, which is why they never met. One day, she found a cheerleader application from Mai, who shared her name, surname, and birthdate. Ai never expected to discover that Mai was the daughter of her father’s first wife, while her own mother was just the mistress. Though hurt, she still hoped her father would acknowledge her. Instead, she was cast out by him and his family. This betrayal left her with a growing desire for revenge.