"Sister, you’re so beautiful." It wasn’t something you would say to a senior who is five years older and whom you’re seeing for the first time. Taerin knew that this wasn’t proper etiquette. It wasn’t a calculated compliment born from a desire to be liked either. It was simply that when Yuyoung appeared before her, she couldn’t find the words to express the wave of emotions that surged within her. And so, for a long time, she lingered around Yuyoung, as a somewhat close junior, never quite getting closer. With the news of Yuyoung’s marriage, Taerin decided to put an end to that exhausting unrequited love. Or at least, she intended to. "Isn’t that Yuyoung unni?" At the chic brunch café 'Dadam (茶啖)' that she visited with her college friend and bestie Da-eun, Taerin unexpectedly reunites with Yuyoung. Trying to avoid her due to the lingering pain of her unrequited love, Yuyoung says something unbelievable to Taerin. "During the time you liked me, I liked you too." It wasn’t unrequited love after all. Yuyoung felt the same way. Overwhelmed by conflicting feelings of resentment and excitement, Taerin finds herself in turmoil. It had only ever been Yuyoung, only ever been her sister. This heart that she can’t seem to let go of, can she really start again?