Hero x Hater? 
Something like my girl highly dislikes your hero. 
She thinks he is ____. Maybe she is friends with your guy out of the hero costume. 
Maybe they fall for another? Or he really likes her, she just doesn't know. 
That's when your guy as the hero saves her. 
She falls for him, seeing him as more? 
Or something like that. Haha 

Pm me.