The Adventures of Onion Head tells the story of "Master Grape is now the mayor of the township, and in order to maintain the dignity of his new position, he has completely abandoned the habit of scratching his head with an awl. Only when he came upon the most difficult matters did he scratch his head twice with a pencil, but this was extremely rare." The Adventures of Onionhead follows the main character, Onionhead, who is a boy with a sense of advocacy and justice. Onionhead's sense of justice and intelligence can be shown in various ways. Old Onion is imprisoned for accidentally stepping on the Lemon King. When Onion Head came to visit the prison, Old Onion told him that all the people in this prison were poor people, none of them had committed any crime, but those who had done bad things were kept in the palace. Onion Head decides to save the good people in the prison, but unfortunately he is also thrown into the black prison. With the help of Mrs. Mole, Little Cherry and Little Strawberry, Onion Head and his friends finally escaped from the prison, and then took over the castle with the villagers, and finally the lemon soldiers laid down their weapons and surrendered. Everyone united, together overthrew the lemon king's rule, and gained freedom.