when there's a difference between what makes your heart flutter & who makes your heart flutter  

After three painful years, Song Yeseul was finally happy. Someone had finally mended the peices of her broken heart back together. Her relationship with Kim Myungsoo was progressing slowly, but she was sure that it was blossoming into something beautiful. He was, after all, the only person who could make her heart flutter in a way she thought it never again could. Though unexpectedly, the moment her first love stepped back into her life, the stiches Myungsoo had sewn came loose. The feelings she thought were long gone were back in an instant. Yeseul could not control the now doubled flutter of her heart.