The First time Kim Taeyeon met Jessica Jung is on December in the last year of High School. That Girl really hates him. Taeyeon meet again with Jessica on December ten years later in Seoul. That Girl still hates him. Thats not the main problem is-Oh!, No! - but the reality is this Girl that hates him is gonna be Kim Taeyeon Fiance arrange by his Grandfather that really like to bug him.  ForewordHello guys, this is the first im writing fanfic so please be nice to me, comment and idea are allowed :)This story is inspired by my favourite author Ilana Tan that has the same tittle of her novel "In a Blue Moon" if you guys Indonesian i bet you know her:)english is not my first language. Oh! and This is genderbender taengsic:) I love taengsic so much! anyway enjoy guys!