The world is covered with fine dust, and Cs, who were injected with expensive antibodies at birth, enjoy a life expectancy of 100 years, while Ns, who were not injected, live a completely different life, with a life expectancy of just 30. Having lived her entire life as a C, 26-year-old college student Io finds out that she was not given the antibody injection at birth thanks to a mistake at the hospital. Now, Io begins to wonder about the life of Ns, which held no interest for her before. She’s especially interested in Joan, the only N in the school. What does life look like when we know what’s coming? The fact that the lives of the two young people who meet in the scheduled time are not clear may not be due to only the clouds of fine dust that hit the world. A story of two young people dreaming of a beautiful future with sincerity and love for each other is touching and unfolds beautifully in an opaque future that does not know how to unfold.