Summarize that main contents of the adventure of the onion,

The Adventures of Onion tells the story that the onion's father, Lao Onion, was put in prison because he accidentally stepped on the foot of the lemon king. When the onion visited the prison, the old onion told him that the prison was full of honest people, while robbers and murderers were kept in the palace of King Lemon. Onion is determined to save the people in prison. However, just as he was preparing to rescue Grandpa Pumpkin and the villagers, he was put into a black prison by the tomato warrior. With the help of voles, cherries and strawberries, he was saved. Later, due to the betrayal of mung bean lawyer, he fell into the hands of tomato soldiers and was put into the prison where Lao cong was. The vole made a hole in the prison and rescued him and all the prisoners. Lemon soldiers laid down their weapons one after another, and everyone overthrew the rule of King Lemon and gained freedom.