On a mysterious night, terrible spores suddenly came to the earth, they drilled into the human body, thus taking it as their own, and taking humans as the target of hunting and devouring. High school student Quan Xinyi (dye Valley General Tai) is also nearly controlled by spores, resulting in a wonderful coexistence with the parasitic animal "Xiaoyou" (Abelong Shi) in his right hand. One day, a new teacher came to the school, Ryoko Tamiya (acted the role of Hanjin), and both she and Xiaoyou were acutely aware of each other's existence. Tamiya introduced A (Wanzuo Ikeuchi) and Hideo Shimada (Dongxiao Changda) to Xiaoyou and invited him to join a network composed entirely of parasitic animals to seek development. During this period, Xinyi and Xiaoyou are ambushed by A, and their dependent mother (Yu Guimeizi) is also inadvertently reduced to the captivity of parasites. In order to protect the most important people, a new one attacks the ferocious parasite. This film is based on Yan Mingjun's cartoon of the same name.