This is the second book in a series of 8 books entitled Class (2) is Unusual. It describes an interesting story that happened in a special class called "cat and mouse class", which is entering the second grade of primary school. There are many children full of personalities in the class, such as smart An Feichi, naughty Ru Ziniu, sensible Yuan Shuai, and unworried Mao Yangyang. From the perspective of children, the author selects interesting stories that happened when they just entered the first grade of primary school.