The story of Happy Birthday, Dad is simple and fun. Dad's birthday was approaching and the little girl wanted to give Dad a birthday present, but she had no idea. So she went to ask the little friends in the kindergarten. The gifts that the friends gave to her dad were of many kinds, which makes people laugh and feel warm. These are the purest sincerity in the children's world. Finally, the little girl gave Dad a special gift. What is it?