- THE UNEXPECTED SERIES : BOOK I - Devastated by the sudden confession from her boyfriend, Park Edlyn decided to go to the rooftop to clear her mind. That is until she met Sim Jake, a handsome neurosurgeon who worked at her father's hospital. They both decided to get drunk and tell each other life stories. It was going so well until they both woke up sober in the same hotel room with marriage documents on the table. They realised they got married due to a drunken mistake but both of their families didn't want them to get an annulment because it would ruin their reputation. Can Edlyn and Jake live together without having the urge to kill each other?

- THE UNEXPECTED SERIES : BOOK II - Daera came back to Seoul as an intern at the Park Specialist Hospital, knowing she would have to see Sunghoon who broke her heart, every day. But little did she know, her heart started growing for Jay, who has always been a gentleman to her. Will she ever know her true feelings? Will she know who has won her heart all the time? Unexpected murders happened too often that made them suspicious of something. Daera, Sunghoon and Jay must find the culprit behind all of the murders and the reason for it.

- THE UNEXPECTED SERIES : BOOK III - There's a story that Heeseung never told his friends. A story that took place 14 years ago. Edlyn was never his first love. It was Jung Areum. A girl who gets on his nerves a lot and who always catches his attention every time. So what made him forget her? What made him decide to move on? What made him and his best friend, Beomgyu drift apart? Read more to find out about Areum, Heeseung and Beomgyu's love triangle.

- THE UNEXPECTED SERIES : LAST BOOK - Winning against Bina was the only reason why Daeun entered medical school. She was tired of seeing her mother being bullied by her aunt and she wanted to put an end to it. That is when she met Sunghoon, the man who talked to her during the night she was admitted to the Park Specialist Hospital. The man who spent time with her during the party in California. She wanted to hug him, tell him that she has been searching for him for months. But she was hesitant as soon as she realised that Sunghoon was her cousin's long-time crush. And she didn't want to be the girl who steals someone else's crush. Will she ever succeed in moving on?