Maybe she's scared of commitment or has trust issues. Or perhaps she feels like the hero is too intense or overwhelming for her.
The heroine might run from the hero because she's afraid of getting hurt. Maybe she sees something in the hero that reminds her of a painful past. Or it could be that she's focused on her career or personal goals and thinks a relationship will hold her back.
Maybe he's trying to protect her from some danger or threat. Or it could be that he's worried about how others will react to their relationship.
One possible reason could be a misunderstanding. Maybe the hero misinterprets the heroine's actions or words and lashes out with an insult.
One possible reason could be that the hero has a bad reputation in the society they live in. Maybe he is known for being a playboy or having a cruel streak, which makes the heroine despise him.
One possible reason could be a misunderstanding. Maybe there was some miscommunication in the past that led the hero to form a negative opinion of the heroine. For example, he might have overheard something that was misinterpreted.
One reason could be that he thinks they are too unrealistic. Heroine novels often have elements of fantasy and over - the - top romance, which might not appeal to his more practical or down - to - earth nature.
Perhaps the hero hides her out of jealousy or possessiveness. The result might be a lot of drama and misunderstandings before they finally work things out.
A prevalent reason is pride. If the heroine has somehow humiliated the hero publicly, his pride gets hurt and he wants to get back at her. This could be as simple as her rejecting him in front of others. Also, there could be a family feud involved. If their families are on opposite sides of a conflict, the hero might feel obliged to take revenge on the heroine as part of that feud, even though they are attracted to each other.
Perhaps she's under the influence of a powerful genjutsu. Genjutsu can distort one's perception and make them do things they wouldn't normally do. In this case, Kushina might be seeing Naruto as an enemy in the genjutsu and thus hurt him. Or it could be a test in a very extreme way. She might think that by putting Naruto through pain, she can make him stronger, although this is a very cruel way of thinking.
Another reason could be related to a prophecy. If there was a prophecy in the fanfiction that Naruto would bring great destruction in the future, and Kushina, being a self - sacrificing mother, might think that killing him is the only way to prevent that destruction, even though it goes against her natural love for her son.
One possible reason could be that Hermione realizes she has feelings for Ron and wants to avoid any confusion or mixed signals with Harry. She might think that by pushing Harry away, she can focus on her true feelings for Ron.