Suzie is an American woman living in Kyoto, Japan, whose life is upended when her husband and son disappear in a mysterious plane crash. As a consolation, her husband's electronics company gives her one of their new class of domestic robots named Sunny.

At first Suzie resents Sunny's attempts to fill the void in her life, but they gradually develop an unexpected friendship. Together they start to uncover the dark truth of what really happened to Suzie's family and become dangerously wrapped up in a world Suzie never knew existed.