Lee Donghae found Jessica sleeping outside his house and she was just wearing a white one-piece dress. Did she escape from the hospital with her memories erased or is she something else? 

From what Donghae sees, Jessica doesn't know how to do her own personal grooming, neither does she know how to use a spoon the correct way.  It was like she was a new-born, trying to learn to walk and knows nothing. 

To Donghae, Jessica is a mystery but one thing for sure, she spells T-R-O-U-B-L-E. 

Living with Donghae, Jessica learns about stuffs she needs to know from Donghae. Sometimes, learning too much for her makes her curious and in turn, she's messing things up for Donghae. 

Other than learning to do the simplest and easiest thing on Earth, what else will Jessica learn? 

And what exactly is Jessica's identity? 

There's more that meets the eyes...