The story begins with the creation of two quantum AIs: Kuro and Shiro. Dr. KE builds them with the intention of having these two AIs accompany and grow alongside his cryogenically frozen son, forging a unique friendship. After going through the five episodes of Q18, Kuro and Shiro gradually learn about human nature, evolving consciousness and emotions. Simultaneously, by connecting the quantum computer with the human brain, they assist the young boy with cryogenic syndrome in capturing love and friendship. Just as this utopian existence takes shape, Dr. KE believes that technology has spiraled out of control. He decides to personally destroy Kuro and Shiro, leading to an intense conflict with his son.