Omg It's not like she purposely made friends with blonde hair.
And she doesn't think black hair is really in love with her, she just thinks he's interested and that's why there's a heart.
She can't just stop being friends with blonde hair like this what the he**!!!
Even if he sees blond hair as a rival, he just has to confess his feelings in fact!! all she wants now is to survive and so she wants to keep him interested in her!!! Understand???