Um Da-da (Bang Min-ah) is a special effects makeup artist. She is secretly dating the popular actor Ma Wang-joon (Hong Jong-hyun), who is on the rise. As Wang-joon gets busy because of work and tired of their relationship, their seven-year-long relationship ends. And that is when Zero Nine (Young-gu) (Yeo Jin-goo), a humanoid robot who is programmed to be in love with his one and only girlfriend, appears in her life. An accidental kiss activates Young-gu and he takes Da-da as his girlfriend. As Da-da and Young-gu get closer and fall for each other, a mystery man tries to harm Da-da by threatening her to break up with Wang-joon, who secretly wants her back. Meanwhile, Diana (Hong Seo-young), the original owner of Zero Nine, comes after them to take Young-gu back. In the end, My Absolute Boyfriend is about the love with a robot who is humane and unstinting. Throughout the series, Young-gu shows what true love is as he learns about love and becomes the absolute boyfriend.