"I promise to protect Yanna but not her, HER! That girl is just a nobody and I don't care if she looks like my dead girlfriend and she is not Yanna! Yanna's dead for godsake!"

 After the death of his girl, Cho Yan Na, Kai and his friends went back to Seoul. For the members, this thing will help Kai to move on from the big event that happened but as far as they know, it's not. Having their lives back as college students, they stayed at a place far from the main city but near to their University and there the daughter of the landlord Yanna will help them to take memories back at their homeplace as their tour guide. For Yanna's point of view, she can claim extra money by this work as a tour guide for her to continue studying but for Exo, its a big thing they can't handle.