She was his first love. She taught him love. She made him believe in love until one day, she got into a car accident. Her mother uses  this opportunity to separate  them both since she doesn’t like their relationship together. 

Her mother lies...... and both of them believe.

That’s when he changes. He becomes cold hearted. He plays with girls’ heart. He doesn’t believe in love anymore because the girl that made him believe in love which was his first love is also the first girl that made his heart broken.