Two adult men who have lived with their parents all their years and cannot grow up in any way, must now change their lives. One's father will marry the other's mother, and they will now be step brothers. Besides the fact that Brennan and his new relative Dale will live in the same house, the main characters will have to share one room. Of course, this joke of fate does not please the characters from the movie Step Brothers 4K. But there is some worse news for Dale and his new brother Brennan. Parents are telling the adult boys that they no longer intend to financially support them. The main protagonists, who have been dependent on their parents since birth, must now look for job. For brothers, this is a difficult task. But it's not all bad news for the heroes. They learn that the parents intend to sell the house. But, Dale and Brennan are not going to put up with it. The protagonists interfere with the sale of the house in various ways. But to fulfill their plans, they must become real brothers!