Lulli is part of the latest Generation of robots that were sold in 22th Century. Her generation was very popular until a fatal flaw was detected: They were too energetic. This made all of customers return them. Afterwards, they were demolished, except for Lulli, who was modified and sent to the past by criminals who sought to kill Nobita in order to change past history and destroy their plan to hack into military data by using her as an assassin.