The series is based on the novel The Dark Manual by Colin O'Sullivan, an Irish writer living in Japan. Suzy (Rashida Jones) is an American woman living in Kyoto, Japan, whose life is turned upside down when her husband and son disappear in a mysterious plane crash. As "consolation", she gets Sunny, a new home robot made by her husband's electronics company. At first, Suzy is repulsed by Sunny's attempt to fill the void in her life, but gradually, they develop an unexpected friendship. Together, they uncover the dark truth about what happened to Suzy's family and are drawn into a dangerous world that Suzy has never known.