Simplify the following text for a Grade 4 native English-speaking person.
Original: Amir is a selfish friend to Hassan , who is devoted and loyal to Amir . One day , he hides in fear as Hassan is beaten and raped by three bullies , led by a boy called Assef , when Hassan refuses to give them a kite that he found for Amir .
Simplified: Hassan refuses to give up Amir 's kite .