Go Mi-Ran (Won Jin-ah) and Ma Dong-chan (Ji Chang-wook) participates in a freezing experiment, which they are told they will be awake in 24 hours. However, something happens and they wake up only 20 years later.

They also find out that they have to keep their body temperature at 31.5 degrees Celsius (About 88.7 Fahrenheit) to survive.

All the people Mi-ran and Dong-chan once knew have aged by 20 years, but their own bodies and memories have not changed at all. Also, they are threatened by an issue now that cause their temperature to rise up, love.

Are they able to find out why both of them are frozen for 20 years?