"Smile for me just once, Sehun~ I'll give you this candy!" I smiled teasingly waving a cutely wrapped candy in his face. "You idiot! That's just a Vitamin C supplement wrapped in a empty candy wrapper! You think I'm that stupid?" Sehun spat back. Ugh. Such a tricky kid... but I WILL make you smile, just you wait Oh Sehun. 

While volunteering for her father's hospital in Seoul, Park Himchan makes a new friend she wasn't expecting to befriend: an alluring boy with prince like looks and a cold stare. His name is Oh Sehun. Being hospitalized after a collapse, Sehun's smile has been drained away by the plain white hospital walls. Park Himchan is determined to change that and bring back his lost laughter the dry and humorless hospital had stolen from him.

(Because who doesn't love Sehun's smile, right?)