Even if it takes a billion years. I will keep my promise with that person. On the day of the burial, Cheol's heart felt strange, a little sad, a little angry, and a little scared. He lived with his father, Dr. Choi Jin-soo, in the Homo Mater's garden in Pyongyang. His father forbids him to leave the park, which is a legacy of independence, due to the frequent civil wars and instability in Korea. Therefore, he has never had any contact with the outside world in his seventeen years of life, and he only interacts with the researcher's family in the park, and is usually accompanied by his three cats, named Descartes, Galileo, and Kant, until one day, in order to surprise his father, he sneaks out to the outside of the park... ...and never returned home.