Four years ago, Bae Sumin has had her very first hearbreak from her very first and only love. Sumin back then has sworn to herself to never fall in love again and most importantly to never forgive Sieun for breaking her heart.  Four years later, on an ordinary night, right when Sumin is returning back to her apartment though her life is meant to turn upside down because a curtain Park Sieun is back in town. And no matter how Sumi