The story begins with the creation of two quantum artificial intelligences, Kuro and Shiro: Dr. Kuro created two quantum AIs, Kuro and Shiro, so that they can accompany his son who is a frozen man as he grows up. After experiencing the five unit stories of Q18, Kuro and Shiro gradually learned about human nature and evolved consciousness and emotions. They also helped the frozen boy to gain love and friendship by connecting the quantum computer with the human brain. But when this beautiful utopia came, the doctor thought that technology had gone out of control and decided to destroy Kuro and Shiro himself...