A new robot, 7723, which is about to be used to save mankind meets Su Xiaomai, a naughty girl who loves football. But she grows in an incomplete family. The father leaves home for the dream, causes Su also to be affected, the character is cold and lonely. The emergence of 7723 also makes the happy enemy gradually become a pair of close friends in love and hating each other. However, the good times does not last long. Boss Pang, with the dream of destroying mankind, traces the whereabouts of 7723. In order to protect Su, 7723 has to format and returns to the initial state of the combat machine. However, the gentle colors and brilliant times engraved with Su Xiaomai have long left indelible marks in his life.