After an explosion in the high school chemistry lab, Ah Mi opens her eyes in the hospital room. Her memory remains stuck in the past from 16 years ago, even though it’s currently 2013. Ah Mi searched piteously for her boyfriend at the time, Jo Yeong Kyeong. For whatever reason, none of her friends ever mention Yeong Kyeong. What's even more strange is that all those involved in the explosion remain at the hospital where Ah Mi was hospitalized.