This set of books organically combines the various problems encountered by primary school students in their studies, such as learning methods, study habits, etc., Into one protagonist, "Doudou", and vividly displays them through the stories that happen to him. This writing method is rare in such books, very novel, and has a strong integrity. The stories are all exciting, humorous, and true; the problems are all sharp and typical, and the tricks are used appropriately and effectively, making it easy to enjoy every page. Coupled with the further subdivision of the primary school stage (divided into three editions, this edition is suitable for fifth and sixth grade primary school students to read, double-color printing), the pertinence is self-evident. "Doudou" is the best and worst child in our minds, acting out a story of both good and evil. It is full of fun to read, and it is actually an ideal state for parent-child reading.