Plot line above for this movie is incorrect

The father and son do not open a "brothel." It is a harem. They are not hiring these women out to other men. It is a "harem" movie, much like many anime series (with or without the eroticism.) Also, I would disagree with this movie being "infantile." It is, rather, adolescent. Mainly, it is two men moving from the "innocence" of a totally predictable life--even though many of the things in that life are not innocent, such as cutthroat business maneuvers--to a new life of unexpected charm and frightening consequences. Very much like the unavoidable and sometimes saddening change from childhood to adulthood. Thus, this is a film about adolescence. Adolescence, for boys at least, being the time when one finds there are other women beyond the mother, and that they have other aspects to them beyond comforting and nurturing. For girls, it is probably different, and I do not presume to ever be able to understand women (the one thing on which I concur with Dr. Freud.) I would not call this movie immature. It has too many subtle nuances and too many little details that might escape the notice of the, let us say, unobservant viewer. The film is silly by intent, but serious in scope. The characters are bigger than life and act in ways that many "real" people would not because they are archetypes. It may not be a "great" film (interpret that word as you may) but it is unique, and makes a serious attempt at teaching something. If you learned something from this film, it succeeded.