The squirrels Xiaomei, Xiaoku and Xiaojian from the forest have different personalities. They were chased by the mountain cat and came to the city. They met the 18-year-old boy Zhang Guoguo and started a happy daily life. Each squirrel has its own characteristics. Xiaomei is good at invention and creation, Xiaoku is serious, has a high IQ, and loves street dance and kung fu; while Xiaojian is greedy, active, and has great strength. Guoguo, who likes to make delicious food, lacks self-confidence in his personality. He always feels that he can't protect his childhood friend Le'er, and the squirrels are also being chased by mountain cats. So the squirrels came up with a good idea. They provided props for Guoguo, assisted Guoguo in helping the weak and becoming a hero who helps others, while also protecting himself. With the help of the squirrels, Guoguo constantly thwarted the mountain cat's plan, prevented the evil actions of the city's bad guys, and helped people solve various difficulties. However, Guoguo, who is low-key by nature, concealed his identity from everyone. After taking off his hero costume, he was still like an ordinary boy next door. Together with his good friends Le'er, squirrel Xiaomei, Xiaoku and Xiaojian, he lived a happy and adventurous city life.