In a world devastated by a fine dust pollution, society has been divided into two castes: the "Cs" (Clean) are those who can afford a vaccine at birth which permits a 100-year lifespan and the "Ns" (Non-clean) are those who can't and will usually die by the time they are 30. Two young women who share the same tragic fate take comfort in each other's company.
| Actor | Role |
|---|---|
 Kim Bo-raJoan | Joan |
 Choi Sung-eunYi Oh | Yi Oh |
 Yoon Jung-hoonKyung | Kyung |
 Kim Joo-ryoungKim Jung Won | Kim Jung Won |
 Lee Min-ahDoctor | Doctor |
| LLee Yoo-JinN Town Tour Guide | N Town Tour Guide |
 Byun Yun-jeongProfessor | Professor |
 Moon Dong-hyeokNot listed | Not listed |
 Lee SeolShin Yi-jeong | Shin Yi-jeong |