Your Unexpected Deceiver"

Amy was a shy, quiet yet a very talented girl and her childhood friend and her neighbor, Rina was a very social person. She was usually partying with her other friends while Amy was answering all of Rina's assignments.
Rina took advantage of Amy since she was 13 years old and up until she was 17 years old, it was always Amy doing everything for her childhood friend, Rina.
When Amy was doing her and Rina's assignment, Amy's mom told her to buy some medicine for her dad because he was having a terrible cold. Amy understood her father's situation so she headed out of her house and walked towards the pharmacy. After she got the medicine for her father she walked back to her house. On her way she saw a concert outside right beside the grocer store and saw Rina.
She then realize that Rina wasn't busy doing chores, she was busy partying. And Amy felt hurt, because her only friend deceived her..... What will she do?