Kuroo and you used to date for two years and broke it off right before the third year started you both ended on good terms and ended cause he was so busy with volleyball and final exams

Later on he got a new girlfriend who strangely look just like you but she was a real bitch and embarrasses/yells at him

Even with a girlfriend Kuroo would still text you about his day and yours, he would occasionally secretly walk you to class

She isn't you, she's an off-brand version of you a copycat