A brilliant scientist creates a humanoid robot, the Electronic. It runs away from the professor who created it, meets its "twin", the Moscow schoolboy Sergey Sirozhkin. The Electronic becomes Sergey Sirozhkin's friend and assistant, goes to school in his place, learns lessons and completes assignments. The mafia finds out about the Electronic, who decides to kidnap the humanoid. Thus, the Electronic and Seryozha find themselves in many funny and dangerous situations.