A School girl called Go Eun-Byul goes off on a schooltrip to Teongyeong. While in Teongyeong she meets her twin sister Lee Eun-Bi for the first time. Lee Eun-Bi is having a hard time in life and is considering suicide. Lee Eun-Bi replaces Go Eun-Byul's live after her dissapear and have to live like her and lie to everyone.