What is the name of this anime?

well i only saw 4 episodes and then forgot the name please help me :

there was this girl who loved getting complements. she was always top in class and good at everything she does. she was also loved by everyone. At home she was always studying like crazy nothing like her outside character. she also had 2 sisters. then this boy came and sort of like took her place. she started working harder at everything trying to out best him and she finally does. then afterwords he tells her the he loves her. He goes to her house one day to give her a cd and since she didn't know who he was she opened it revealing her true self ( she actually jumped on him) when he found out her true self he started using her to do his work or else he'll expose her.

thats all i remember pls help me