Our protagonist, Hana has a twin sister, Yeong, who was born 3 minutes earlier. Strangely, what happens to Yeong also happens to Hana in exactly 3 days. Then one day, Hana
witnesses Yeong's sudden death. As she looks for the reason for Yeong's death, Hana realizes she might die in 3 days too. Running away aimlessly, Hana finds herself in a distant
place where she suddenly hears a strange voice... It's a narration interpreting her entire life!