What if your past and present intertwined in your future?

Emma Song has just gone through a messy break up and isn't in the mood for another relationship to break her heart.

But her roommate Yunyi won't take any of it and drags her off to the nearest fortune teller shop in town, hoping to lift her spirits.

And even after all the trials Emma claims were nonsense, the wheel of fate never once lied. 

"You will meet three people in your life. One from a forgotten past, another in a regretted timeline - and a third from an unknown future." 

Emma doesn't make much of it, and decides to focus on more productive things - such as finishing her studies abroad in Seoul School of Arts and dealing with her own family back in the states on the phone every weekend. Questions from annoying aunts back home about her boyfriend that no longer exists drive her up the walls, which could be the reason why she hopes to never leave South Korea. 

But she has no idea that she is in the very place where it all started, where the very first of her encounters are coming back to haunt her once more. The words from the fortune teller play back in her mind, after more and more coincedences collide. 

"If you're pushing me away because you don't want to get your heart broken again - Emma, for how long are you going to stay scared?" - Kim Doyoung -

"If I could turn back time, I wouldn't do what I did if I knew the truth, Emma. I'm sorry." -Jung Jaehyun - 

"Everyone's proclaiming their 'only ifs' to you, Emma. What about me? To me, you're not an 'if only' - but you were always my favourite 'what if'." -Moon Taeil-

Emma tries to make sense of all this, of how her past and present are coming for her now. The problem is, why can't she remember most of it?